final KnownBiasTurntableGyroscopeCalibratorListener listener) {
        this(convertPosition(position), turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                listener);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX, final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz,
            final double accelerometerMxy, final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx, final double accelerometerMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

    /**
     * Gets known x-coordinate of gyroscope bias.
     * This is expressed in radians per second (rad/s).
     *
     * @return known x-coordinate of gyroscope bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets known x-coordinate of gyroscope bias.
     * This is expressed in radians per second (rad/s).
     *
     * @param biasX known x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets known y-coordinate of gyroscope bias.
     * This is expressed in radians per second (rad/s).
     *
     * @return known y-coordinate of gyroscope bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets known y-coordinate of gyroscope bias.
     * This is expressed in radians per second (rad/s).
     *
     * @param biasY known y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = biasY;
    }

    /**
     * Gets known z-coordinate of gyroscope bias.
     * This is expressed in radians per second (rad/s).
     *
     * @return known z-coordinate of gyroscope bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets known z-coordinate of gyroscope bias.
     * This is expressed in radians per second (rad/s).
     *
     * @param biasZ known z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = biasZ;
    }

    /**
     * Gets known x-coordinate of gyroscope bias.
     *
     * @return known x-coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedX() {
        return new AngularSpeed(biasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets known x-coordinate of gyroscope bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(biasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known x-coordinate of gyroscope bias.
     *
     * @param biasX known x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final AngularSpeed biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAngularSpeed(biasX);
    }

    /**
     * Gets known y-coordinate of gyroscope bias.
     *
     * @return known y-coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedY() {
        return new AngularSpeed(biasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets known y-coordinate of gyroscope bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(biasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param biasY known y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final AngularSpeed biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = convertAngularSpeed(biasY);
    }

    /**
     * Gets known z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return known z-coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedZ() {
        return new AngularSpeed(biasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets known z-coordinate of gyroscope bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(biasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known z-coordinate of gyroscope bias.
     *
     * @param biasZ known z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final AngularSpeed biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = convertAngularSpeed(biasZ);
    }

    /**
     * Sets known bias coordinates of gyroscope expressed in radians
     * per second (rad/s).
     *
     * @param biasX known x-coordinate of gyroscope bias.
     * @param biasY known y-coordinate of gyroscope bias.
     * @param biasZ known z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(
            final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
        this.biasY = biasY;
        this.biasZ = biasZ;
    }

    /**
     * Sets known bias coordinates of gyroscope.
     *
     * @param biasX known x-coordinate of gyroscope bias.
     * @param biasY known y-coordinate of gyroscope bias.
     * @param biasZ known z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(
            final AngularSpeed biasX, final AngularSpeed biasY, final AngularSpeed biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAngularSpeed(biasX);
        this.biasY = convertAngularSpeed(biasY);
        this.biasZ = convertAngularSpeed(biasZ);
    }

    /**
     * Gets known gyroscope bias.
     *
     * @return known gyroscope bias.
     */
    public AngularSpeedTriad getBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known gyroscope bias.
     *
     * @param result instance where result will be stored.
     */
    public void getBiasAsTriad(final AngularSpeedTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known gyroscope bias.
     *
     * @param bias gyroscope bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setBias(final AngularSpeedTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAngularSpeed(bias.getValueX(), bias.getUnit());
        biasY = convertAngularSpeed(bias.getValueY(), bias.getUnit());
        biasZ = convertAngularSpeed(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets initial x scaling factor of gyroscope.
     *
     * @return initial x scaling factor of gyroscope.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor of gyroscope.
     *
     * @return initial y scaling factor of gyroscope.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor of gyroscope.
     *
     * @param initialSy initial y scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor of gyroscope.
     *
     * @return initial z scaling factor of gyroscope.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor of gyroscope.
     *
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error of gyroscope.
     *
     * @return initial x-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error of gyroscope.
     *
     * @return initial x-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error of gyroscope.
     *
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error of gyroscope.
     *
     * @return initial y-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error of gyroscope.
     *
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error of gyroscope.
     *
     * @return initial y-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error of gyroscope.
     *
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error of gyroscope.
     *
     * @return initial z-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error of gyroscope.
     *
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error of gyroscope.
     *
     * @return initial z-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error of gyroscope.
     *
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @param initialSy initial y scaling factor of gyroscope.
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors of
     * gyroscope.
     *
     * @param initialSx  initial x scaling factor of gyroscope.
     * @param initialSy  initial y scaling factor of gyroscope.
     * @param initialSz  initial z scaling factor of gyroscope.
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known gyroscope bias as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinates of gyroscope bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets known gyroscope bias as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets known gyroscope bias  as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param bias known bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (bias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        biasX = bias[0];
        biasY = bias[1];
        biasZ = bias[2];
    }

    /**
     * Gets known gyroscope bias as a column matrix.
     * Matrix values are expressed in radians per second (rad/s).
     *
     * @return known gyroscope bias as a column matrix.
     */
    @Override
    public Matrix getBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known gyroscope bias as a column matrix.
     * Matrix values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, biasX);
        result.setElementAtIndex(1, biasY);
        result.setElementAtIndex(2, biasZ);
    }

    /**
     * Sets known gyroscope bias as a column matrix.
     * Matrix values are expressed in radians per second (rad/s).
     *
     * @param bias known gyroscope bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setBias(final Matrix bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (bias.getRows() != BodyKinematics.COMPONENTS || bias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        biasX = bias.getElementAtIndex(0);
        biasY = bias.getElementAtIndex(1);
        biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @return constant rotation rate of turntable.
     */
    public double getTurntableRotationRate() {
        return turntableRotationRate;
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final double turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (turntableRotationRate <= 0.0) {
            throw new IllegalArgumentException();
        }

        this.turntableRotationRate = turntableRotationRate;
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @return constant rotation rate of turntable.
     */
    public AngularSpeed getTurntableRotationRateAsAngularSpeed() {
        return new AngularSpeed(turntableRotationRate, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @param result instance where result will be stored.
     */
    public void getTurntableRotationRateAsAngularSpeed(final AngularSpeed result) {
        result.setValue(turntableRotationRate);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final AngularSpeed turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTurntableRotationRate(convertAngularSpeed(turntableRotationRate));
    }

    /**
     * Gets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @return time interval between measurements.
     */
    public double getTimeInterval() {
        return timeInterval;
    }

    /**
     * Sets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTimeInterval(final double timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (timeInterval <= 0.0) {
            throw new IllegalArgumentException();
        }
        this.timeInterval = timeInterval;
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @return time interval between measurements.
     */
    public Time getTimeIntervalAsTime() {
        return new Time(timeInterval, TimeUnit.SECOND);
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @param result instance where result will be stored.
     */
    public void getTimeIntervalAsTime(final Time result) {
        result.setValue(timeInterval);
        result.setUnit(TimeUnit.SECOND);
    }

    /**
     * Sets time interval between measurements being captured.
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTimeInterval(final Time timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTimeInterval(convertTime(timeInterval));
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyKinematics> getMeasurements() {

final Matrix accelerometerMa, final KnownBiasEasyGyroscopeCalibratorListener listener) {
        this(sequences, commonAxisUsed, estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias,
                accelerometerMa);
        this.listener = listener;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX, final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx, final double accelerometerMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz,
            final double accelerometerMxy, final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx, final double accelerometerMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx, accelerometerMyz,
                accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

    /**
     * Gets x-coordinate of gyroscope known bias.
     * This is expressed in radians per second (rad/s).
     *
     * @return x-coordinate of gyroscope known bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets x-coordinate of gyroscope known bias.
     * This is expressed in radians per second (rad/s).
     *
     * @param biasX x-coordinate of gyroscope known bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets y-coordinate of gyroscope known bias.
     * This is expressed in radians per second (rad/s).
     *
     * @return y-coordinate of gyroscope known bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets y-coordinate of gyroscope known bias.
     * This is expressed in radians per second (rad/s).
     *
     * @param biasY y-coordinate of gyroscope known  bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = biasY;
    }

    /**
     * Gets z-coordinate of gyroscope known bias.
     * This is expressed in radians per second (rad/s).
     *
     * @return z-coordinate of gyroscope known bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets z-coordinate of gyroscope known bias.
     * This is expressed in radians per second (rad/s).
     *
     * @param biasZ z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = biasZ;
    }

    /**
     * Gets x-coordinate of gyroscope known bias.
     *
     * @return x-coordinate of gyroscope known bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedX() {
        return new AngularSpeed(biasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets x-coordinate of gyroscope known bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(biasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets x-coordinate of gyroscope known bias.
     *
     * @param biasX x-coordinate of gyroscope known bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final AngularSpeed biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAngularSpeed(biasX);
    }

    /**
     * Gets y-coordinate of gyroscope known bias.
     *
     * @return y-coordinate of gyroscope known bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedY() {
        return new AngularSpeed(biasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets y-coordinate of gyroscope known bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(biasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets y-coordinate of gyroscope known bias.
     *
     * @param biasY y-coordinate of gyroscope known bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final AngularSpeed biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = convertAngularSpeed(biasY);
    }

    /**
     * Gets z-coordinate of gyroscope known bias.
     *
     * @return initial z-coordinate of gyroscope known bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedZ() {
        return new AngularSpeed(biasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets z-coordinate of gyroscope known bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(biasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets z-coordinate of gyroscope known bias.
     *
     * @param biasZ z-coordinate of gyroscope known bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final AngularSpeed biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = convertAngularSpeed(biasZ);
    }

    /**
     * Sets known bias coordinates of gyroscope expressed in
     * radians per second (rad/s).
     *
     * @param biasX x-coordinate of gyroscope known bias.
     * @param biasY y-coordinate of gyroscope known bias.
     * @param biasZ z-coordinate of gyroscope known bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(
            final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
        this.biasY = biasY;
        this.biasZ = biasZ;
    }

    /**
     * Sets known bias coordinates of gyroscope.
     *
     * @param biasX x-coordinate of gyroscope known bias.
     * @param biasY y-coordinate of gyroscope known bias.
     * @param biasZ z-coordinate of gyroscope known bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final AngularSpeed biasX, final AngularSpeed biasY, final AngularSpeed biasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAngularSpeed(biasX);
        this.biasY = convertAngularSpeed(biasY);
        this.biasZ = convertAngularSpeed(biasZ);
    }

    /**
     * Gets known gyroscope bias.
     *
     * @return known gyroscope bias.
     */
    public AngularSpeedTriad getBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known gyroscope bias.
     *
     * @param result instance where result will be stored.
     */
    public void getBiasAsTriad(final AngularSpeedTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known gyroscope bias.
     *
     * @param bias gyroscope bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setBias(final AngularSpeedTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAngularSpeed(bias.getValueX(), bias.getUnit());
        biasY = convertAngularSpeed(bias.getValueY(), bias.getUnit());
        biasZ = convertAngularSpeed(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets initial x scaling factor of gyroscope.
     *
     * @return initial x scaling factor of gyroscope.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor of gyroscope.
     *
     * @return initial y scaling factor of gyroscope.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor of gyroscope.
     *
     * @param initialSy initial y scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor of gyroscope.
     *
     * @return initial z scaling factor of gyroscope.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor of gyroscope.
     *
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error of gyroscope.
     *
     * @return initial x-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error of gyroscope.
     *
     * @return initial x-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error of gyroscope.
     *
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error of gyroscope.
     *
     * @return initial y-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error of gyroscope.
     *
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error of gyroscope.
     *
     * @return initial y-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error of gyroscope.
     *
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error of gyroscope.
     *
     * @return initial z-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error of gyroscope.
     *
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error of gyroscope.
     *
     * @return initial z-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error of gyroscope.
     *
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @param initialSy initial y scaling factor of gyroscope.
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(final double initialSx, final double initialSy, final double initialSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors of
     * gyroscope.
     *
     * @param initialSx  initial x scaling factor of gyroscope.
     * @param initialSy  initial y scaling factor of gyroscope.
     * @param initialSz  initial z scaling factor of gyroscope.
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets gyroscope known bias as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinates of gyroscope known bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets gyroscope known bias as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets gyroscope known bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param bias known bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (bias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        biasX = bias[0];
        biasY = bias[1];
        biasZ = bias[2];
    }

    /**
     * Gets gyroscope known bias as a column matrix.
     * Matrix values are expressed in radians per second (rad/s).
     *
     * @return initial gyroscope bias to be used to find a solution as a
     * column matrix.
     */
    @Override
    public Matrix getBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets gyroscope known bias as a column matrix.
     * Matrix values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, biasX);
        result.setElementAtIndex(1, biasY);
        result.setElementAtIndex(2, biasZ);
    }

    /**
     * Sets gyroscope known bias as a column matrix.
     * Matrix values are expressed in radians per second (rad/s).
     *
     * @param bias gyroscope known bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setBias(final Matrix bias) throws LockedException {

}

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX, final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz,
            final double accelerometerMxy, final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx, final double accelerometerMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of gyroscope bias ot be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedX() {
        return new AngularSpeed(initialBiasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(initialBiasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final AngularSpeed initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedY() {
        return new AngularSpeed(initialBiasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(initialBiasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final AngularSpeed initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAngularSpeed(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedZ() {
        return new AngularSpeed(initialBiasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(initialBiasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final AngularSpeed initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution
     * expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final double initialBiasX, final double initialBiasY, final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final AngularSpeed initialBiasX, final AngularSpeed initialBiasY, final AngularSpeed initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
        this.initialBiasY = convertAngularSpeed(initialBiasY);
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Gets initial x scaling factor of gyroscope.
     *
     * @return initial x scaling factor of gyroscope.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor of gyroscope.
     *
     * @return initial y scaling factor of gyroscope.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor of gyroscope.
     *
     * @param initialSy initial y scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor of gyroscope.
     *
     * @return initial z scaling factor of gyroscope.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor of gyroscope.
     *
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error of gyroscope.
     *
     * @return initial x-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error of gyroscope.
     *
     * @return initial x-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error of gyroscope.
     *
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error of gyroscope.
     *
     * @return initial y-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error of gyroscope.
     *
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error of gyroscope.
     *
     * @return initial y-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error of gyroscope.
     *
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error of gyroscope.
     *
     * @return initial z-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error of gyroscope.
     *
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error of gyroscope.
     *
     * @return initial z-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error of gyroscope.
     *
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @param initialSy initial y scaling factor of gyroscope.
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors of
     * gyroscope.
     *
     * @param initialSx  initial x scaling factor of gyroscope.
     * @param initialSy  initial y scaling factor of gyroscope.
     * @param initialSz  initial z scaling factor of gyroscope.
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinates of initial gyroscope bias.
     */
    public double[] getInitialBias() {
        final double[] result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @return initial gyroscope bias to be used to find a solution as a
     * column matrix.
     */
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * a column matrix with values expressed in radians per second (rad/s).
     *
     * @param initialBias initial gyroscope bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @return initial bias coordinates.
     */
    public AngularSpeedTriad getInitialBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    public void getInitialBiasAsTriad(AngularSpeedTriad result) {

}

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX,
            final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy,
            final double accelerometerSz, final double accelerometerMxy,
            final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx,
            final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of gyroscope bias ot be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedX() {
        return new AngularSpeed(initialBiasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(initialBiasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final AngularSpeed initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedY() {
        return new AngularSpeed(initialBiasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(initialBiasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final AngularSpeed initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAngularSpeed(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedZ() {
        return new AngularSpeed(initialBiasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(initialBiasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final AngularSpeed initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution
     * expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final double initialBiasX, final double initialBiasY, final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final AngularSpeed initialBiasX, final AngularSpeed initialBiasY, final AngularSpeed initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
        this.initialBiasY = convertAngularSpeed(initialBiasY);
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Gets initial x scaling factor of gyroscope.
     *
     * @return initial x scaling factor of gyroscope.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor of gyroscope.
     *
     * @return initial y scaling factor of gyroscope.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor of gyroscope.
     *
     * @param initialSy initial y scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor of gyroscope.
     *
     * @return initial z scaling factor of gyroscope.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor of gyroscope.
     *
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error of gyroscope.
     *
     * @return initial x-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error of gyroscope.
     *
     * @return initial x-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error of gyroscope.
     *
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error of gyroscope.
     *
     * @return initial y-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error of gyroscope.
     *
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error of gyroscope.
     *
     * @return initial y-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error of gyroscope.
     *
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error of gyroscope.
     *
     * @return initial z-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error of gyroscope.
     *
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error of gyroscope.
     *
     * @return initial z-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error of gyroscope.
     *
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @param initialSy initial y scaling factor of gyroscope.
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors of
     * gyroscope.
     *
     * @param initialSx  initial x scaling factor of gyroscope.
     * @param initialSy  initial y scaling factor of gyroscope.
     * @param initialSz  initial z scaling factor of gyroscope.
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinates of initial gyroscope bias.
     */
    public double[] getInitialBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @return initial gyroscope bias to be used to find a solution as a
     * column matrix.
     */
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * a column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial gyroscope bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @return initial bias coordinates.
     */
    public AngularSpeedTriad getInitialBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    public void getInitialBiasAsTriad(AngularSpeedTriad result) {

final RobustTurntableGyroscopeCalibratorListener listener) {
        this(convertPosition(position), turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                estimateGDependentCrossBiases, initialBias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                listener);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX, final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz,
            final double accelerometerMxy, final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx, final double accelerometerMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of gyroscope bias ot be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedX() {
        return new AngularSpeed(initialBiasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(initialBiasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final AngularSpeed initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedY() {
        return new AngularSpeed(initialBiasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(initialBiasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final AngularSpeed initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAngularSpeed(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedZ() {
        return new AngularSpeed(initialBiasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(initialBiasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final AngularSpeed initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution
     * expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final double initialBiasX, final double initialBiasY, final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final AngularSpeed initialBiasX, final AngularSpeed initialBiasY, final AngularSpeed initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
        this.initialBiasY = convertAngularSpeed(initialBiasY);
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Gets initial x scaling factor of gyroscope.
     *
     * @return initial x scaling factor of gyroscope.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor of gyroscope.
     *
     * @return initial y scaling factor of gyroscope.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor of gyroscope.
     *
     * @param initialSy initial y scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor of gyroscope.
     *
     * @return initial z scaling factor of gyroscope.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor of gyroscope.
     *
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error of gyroscope.
     *
     * @return initial x-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error of gyroscope.
     *
     * @return initial x-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error of gyroscope.
     *
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error of gyroscope.
     *
     * @return initial y-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error of gyroscope.
     *
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error of gyroscope.
     *
     * @return initial y-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error of gyroscope.
     *
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error of gyroscope.
     *
     * @return initial z-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error of gyroscope.
     *
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error of gyroscope.
     *
     * @return initial z-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error of gyroscope.
     *
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @param initialSy initial y scaling factor of gyroscope.
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors of
     * gyroscope.
     *
     * @param initialSx  initial x scaling factor of gyroscope.
     * @param initialSy  initial y scaling factor of gyroscope.
     * @param initialSz  initial z scaling factor of gyroscope.
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinates of initial gyroscope bias.
     */
    public double[] getInitialBias() {
        final double[] result = new double[BodyKinematics.COMPONENTS];

final Matrix accelerometerMa, final EasyGyroscopeCalibratorListener listener) {
        this(sequences, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                accelerometerBias, accelerometerMa);
        this.listener = listener;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX,
            final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy,
            final double accelerometerSz, final double accelerometerMxy,
            final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx,
            final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of gyroscope bias ot be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedX() {
        return new AngularSpeed(initialBiasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(initialBiasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final AngularSpeed initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedY() {
        return new AngularSpeed(initialBiasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(initialBiasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final AngularSpeed initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAngularSpeed(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedZ() {
        return new AngularSpeed(initialBiasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(initialBiasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final AngularSpeed initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution
     * expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final double initialBiasX, final double initialBiasY, final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final AngularSpeed initialBiasX, final AngularSpeed initialBiasY, final AngularSpeed initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
        this.initialBiasY = convertAngularSpeed(initialBiasY);
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Gets initial x scaling factor of gyroscope.
     *
     * @return initial x scaling factor of gyroscope.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor of gyroscope.
     *
     * @return initial y scaling factor of gyroscope.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor of gyroscope.
     *
     * @param initialSy initial y scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor of gyroscope.
     *
     * @return initial z scaling factor of gyroscope.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor of gyroscope.
     *
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error of gyroscope.
     *
     * @return initial x-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error of gyroscope.
     *
     * @return initial x-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error of gyroscope.
     *
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error of gyroscope.
     *
     * @return initial y-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error of gyroscope.
     *
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error of gyroscope.
     *
     * @return initial y-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error of gyroscope.
     *
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error of gyroscope.
     *
     * @return initial z-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error of gyroscope.
     *
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error of gyroscope.
     *
     * @return initial z-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error of gyroscope.
     *
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @param initialSy initial y scaling factor of gyroscope.
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors of
     * gyroscope.
     *
     * @param initialSx  initial x scaling factor of gyroscope.
     * @param initialSy  initial y scaling factor of gyroscope.
     * @param initialSz  initial z scaling factor of gyroscope.
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinates of initial gyroscope bias.
     */
    public double[] getInitialBias() {
        final var result = new double[BodyKinematics.COMPONENTS];

}

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX,
            final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy,
            final double accelerometerSz, final double accelerometerMxy,
            final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx,
            final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of gyroscope bias ot be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedX() {
        return new AngularSpeed(initialBiasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(initialBiasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final AngularSpeed initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedY() {
        return new AngularSpeed(initialBiasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(initialBiasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final AngularSpeed initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAngularSpeed(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedZ() {
        return new AngularSpeed(initialBiasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(initialBiasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final AngularSpeed initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution
     * expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final double initialBiasX, final double initialBiasY, final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final AngularSpeed initialBiasX, final AngularSpeed initialBiasY, final AngularSpeed initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
        this.initialBiasY = convertAngularSpeed(initialBiasY);
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Gets initial x scaling factor of gyroscope.
     *
     * @return initial x scaling factor of gyroscope.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor of gyroscope.
     *
     * @return initial y scaling factor of gyroscope.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor of gyroscope.
     *
     * @param initialSy initial y scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor of gyroscope.
     *
     * @return initial z scaling factor of gyroscope.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor of gyroscope.
     *
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error of gyroscope.
     *
     * @return initial x-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error of gyroscope.
     *
     * @return initial x-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error of gyroscope.
     *
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error of gyroscope.
     *
     * @return initial y-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error of gyroscope.
     *
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error of gyroscope.
     *
     * @return initial y-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error of gyroscope.
     *
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error of gyroscope.
     *
     * @return initial z-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error of gyroscope.
     *
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error of gyroscope.
     *
     * @return initial z-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error of gyroscope.
     *
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @param initialSy initial y scaling factor of gyroscope.
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors of
     * gyroscope.
     *
     * @param initialSx  initial x scaling factor of gyroscope.
     * @param initialSy  initial y scaling factor of gyroscope.
     * @param initialSz  initial z scaling factor of gyroscope.
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinates of initial gyroscope bias.
     */
    public double[] getInitialBias() {
        final var result = new double[BodyKinematics.COMPONENTS];

}

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX, final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz,
            final double accelerometerMxy, final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx, final double accelerometerMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of gyroscope bias ot be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find
     * a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedX() {
        return new AngularSpeed(initialBiasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(initialBiasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasX(final AngularSpeed initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedY() {
        return new AngularSpeed(initialBiasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(initialBiasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasY(final AngularSpeed initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAngularSpeed(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    public AngularSpeed getInitialBiasAngularSpeedZ() {
        return new AngularSpeed(initialBiasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param result instance where result data will be stored.
     */
    public void getInitialBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(initialBiasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find a
     * solution.
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBiasZ(final AngularSpeed initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution
     * expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final double initialBiasX, final double initialBiasY, final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(
            final AngularSpeed initialBiasX, final AngularSpeed initialBiasY, final AngularSpeed initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
        this.initialBiasY = convertAngularSpeed(initialBiasY);
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Gets initial x scaling factor of gyroscope.
     *
     * @return initial x scaling factor of gyroscope.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor of gyroscope.
     *
     * @return initial y scaling factor of gyroscope.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor of gyroscope.
     *
     * @param initialSy initial y scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor of gyroscope.
     *
     * @return initial z scaling factor of gyroscope.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor of gyroscope.
     *
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error of gyroscope.
     *
     * @return initial x-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error of gyroscope.
     *
     * @return initial x-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error of gyroscope.
     *
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error of gyroscope.
     *
     * @return initial y-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error of gyroscope.
     *
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error of gyroscope.
     *
     * @return initial y-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error of gyroscope.
     *
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error of gyroscope.
     *
     * @return initial z-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error of gyroscope.
     *
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error of gyroscope.
     *
     * @return initial z-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error of gyroscope.
     *
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @param initialSy initial y scaling factor of gyroscope.
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors of
     * gyroscope.
     *
     * @param initialSx  initial x scaling factor of gyroscope.
     * @param initialSy  initial y scaling factor of gyroscope.
     * @param initialSz  initial z scaling factor of gyroscope.
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinates of initial gyroscope bias.
     */
    public double[] getInitialBias() {
        final double[] result = new double[BodyKinematics.COMPONENTS];

this(measurements, commonAxisUsed, initialBias, initialMg, initialGg);
        this.listener = listener;
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    @Override
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    @Override
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    @Override
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find a solution.
     * This is expressed in radians per second (rad/s).
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a solution.
     *
     * @return initial x-coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getInitialBiasAngularSpeedX() {
        return new AngularSpeed(initialBiasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial x-coordinate of gyroscope bias to be used to find a solution.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(initialBiasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial x-coordinate of gyroscope bias to be used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasX(final AngularSpeed initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a solution.
     *
     * @return initial y-coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getInitialBiasAngularSpeedY() {
        return new AngularSpeed(initialBiasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial y-coordinate of gyroscope bias to be used to find a solution.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(initialBiasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial y-coordinate of gyroscope bias to be used to find a solution.
     *
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasY(final AngularSpeed initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAngularSpeed(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a solution.
     *
     * @return initial z-coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getInitialBiasAngularSpeedZ() {
        return new AngularSpeed(initialBiasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial z-coordinate of gyroscope bias to be used to find a solution.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(initialBiasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial z-coordinate of gyroscope bias to be used to find a solution.
     *
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasZ(final AngularSpeed initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution
     * expressed in radians per second (rad/s).
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(final double initialBiasX, final double initialBiasY, final double initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of gyroscope bias.
     * @param initialBiasY initial y-coordinate of gyroscope bias.
     * @param initialBiasZ initial z-coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(
            final AngularSpeed initialBiasX, final AngularSpeed initialBiasY, final AngularSpeed initialBiasZ)
            throws LockedException {

        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
        this.initialBiasY = convertAngularSpeed(initialBiasY);
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial bias to be used to find a solution as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial bias to be used to find a solution as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial bias to be used to find a solution as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial bias to be used to find a solution as a column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @return initial bias to be used to find a solution as a column matrix.
     */
    @Override
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial bias to be used to find a solution as a column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial bias to be used to find a solution as a column matrix
     * with values expressed in radians per second (rad/s).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @return initial bias coordinates.
     */
    @Override
    public AngularSpeedTriad getInitialBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialBiasAsTriad(final AngularSpeedTriad result) {
        result.setValueCoordinatesAndUnit(initialBiasX, initialBiasY, initialBiasZ,
                AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBias initial bias coordinates to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(final AngularSpeedTriad initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialBiasX = convertAngularSpeed(initialBias.getValueX(), initialBias.getUnit());
        initialBiasY = convertAngularSpeed(initialBias.getValueY(), initialBias.getUnit());
        initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities) and containing the standard
     * deviations of accelerometer and gyroscope measurements.
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public Collection<StandardDeviationFrameBodyKinematics> getMeasurements() {

this(convertAcceleration(groundTruthGravityNorm), measurements, commonAxisUsed, bias, initialMa, listener);
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = biasY;
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = biasZ;
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasXAsAcceleration() {
        return new Acceleration(biasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasXAsAcceleration(final Acceleration result) {
        result.setValue(biasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final Acceleration biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAcceleration(biasX);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasYAsAcceleration() {
        return new Acceleration(biasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasYAsAcceleration(final Acceleration result) {
        result.setValue(biasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final Acceleration biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = convertAcceleration(biasY);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasZAsAcceleration() {
        return new Acceleration(biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasZAsAcceleration(final Acceleration result) {
        result.setValue(biasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets z-coordinate of known accelerometer bias to be used to find a solution.
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final Acceleration biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Sets known bias coordinates of accelerometer expressed in meters
     * per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @param biasY y-coordinate of known accelerometer bias.
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
        this.biasY = biasY;
        this.biasZ = biasZ;
    }

    /**
     * Sets known bias coordinates of accelerometer.
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @param biasY y-coordinate of known accelerometer bias.
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final Acceleration biasX, final Acceleration biasY, final Acceleration biasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAcceleration(biasX);
        this.biasY = convertAcceleration(biasY);
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @return known accelerometer bias.
     */
    @Override
    public AccelerationTriad getBiasAsTriad() {
        return new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getBiasAsTriad(final AccelerationTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known accelerometer bias.
     *
     * @param bias accelerometer bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBias(final AccelerationTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAcceleration(bias.getValueX(), bias.getUnit());
        biasY = convertAcceleration(bias.getValueY(), bias.getUnit());
        biasZ = convertAcceleration(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(final double initialSx, final double initialSy, final double initialSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param bias known bias to be set
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (bias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        biasX = bias[0];
        biasY = bias[1];
        biasZ = bias[2];
    }

    /**
     * Gets known bias as a column matrix.
     *
     * @return known bias as a column matrix.
     */
    @Override
    public Matrix getBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, biasX);
        result.setElementAtIndex(1, biasY);
        result.setElementAtIndex(2, biasZ);
    }

    /**
     * Sets known bias as an array.
     *
     * @param bias bias to be set.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setBias(final Matrix bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (bias.getRows() != BodyKinematics.COMPONENTS || bias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        biasX = bias.getElementAtIndex(0);
        biasY = bias.getElementAtIndex(1);
        biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets ground truth gravity norm to be expected at location where measurements have been made,
     * expressed in meter per squared second (m/s^2).
     *
     * @return ground truth gravity norm or null.
     */
    public Double getGroundTruthGravityNorm() {

this(measurements, commonAxisUsed, magneticModel, initialHardIron, initialMm);
        this.listener = listener;
    }

    /**
     * Gets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronX() {
        return initialHardIronX;
    }

    /**
     * Sets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final double initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
    }

    /**
     * Gets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronY() {
        return initialHardIronY;
    }

    /**
     * Sets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final double initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = initialHardIronY;
    }

    /**
     * Gets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronZ() {
        return initialHardIronZ;
    }

    /**
     * Sets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in meters Teslas (T).
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final double initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final MagneticFluxDensity initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final MagneticFluxDensity initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias coordinates of magnetometer used to find
     * a solution expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final double initialHardIronX, final double initialHardIronY, final double initialHardIronZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
        this.initialHardIronY = initialHardIronY;
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Sets initial hard iron coordinates of magnetometer used to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final MagneticFluxDensity initialHardIronX, final MagneticFluxDensity initialHardIronY,
            final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @return initial hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getInitialHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                initialHardIronX, initialHardIronY, initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(initialHardIronX, initialHardIronY, initialHardIronZ,
                MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial hard-iron used to find a solution.
     *
     * @param initialHardIron initial hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(final MagneticFluxDensityTriad initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialHardIronX = convertMagneticFluxDensity(initialHardIron.getValueX(), initialHardIron.getUnit());
        initialHardIronY = convertMagneticFluxDensity(initialHardIron.getValueY(), initialHardIron.getUnit());
        initialHardIronZ = convertMagneticFluxDensity(initialHardIron.getValueZ(), initialHardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getInitialHardIron(result);
        return result;
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getInitialHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialHardIronX;
        result[1] = initialHardIronY;
        result[2] = initialHardIronZ;
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialHardIron(final double[] initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialHardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialHardIronX = initialHardIron[0];
        initialHardIronY = initialHardIron[1];
        initialHardIronZ = initialHardIron[2];
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @return initial hard-iron bias to be used to find a solution as a
     * column matrix.
     */
    @Override
    public Matrix getInitialHardIronAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getInitialHardIronAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialHardIronAsMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialHardIronX);
        result.setElementAtIndex(1, initialHardIronY);
        result.setElementAtIndex(2, initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as a column
     * matrix with values expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialHardIron(final Matrix initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialHardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || initialHardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialHardIronX = initialHardIron.getElementAtIndex(0);
        initialHardIronY = initialHardIron.getElementAtIndex(1);
        initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public Collection<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {

this(measurements, commonAxisUsed, magneticModel, hardIron, initialMm);
        this.listener = listener;
    }

    /**
     * Gets x-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return x-coordinate of known magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronX() {
        return hardIronX;
    }

    /**
     * Sets x-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronX x coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final double hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
    }

    /**
     * Gets y-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return y-coordinate of known magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronY() {
        return hardIronY;
    }

    /**
     * Sets y-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronY y coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final double hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = hardIronY;
    }

    /**
     * Gets z-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return z-coordinate of known magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronZ() {
        return hardIronZ;
    }

    /**
     * Sets z-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronZ z coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = hardIronZ;
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @return x coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron.
     *
     * @param hardIronX known x-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final MagneticFluxDensity hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @return y coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron.
     *
     * @param hardIronY known y-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final MagneticFluxDensity hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @return z coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron.
     *
     * @param hardIronZ known z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Sets known hard-iron bias coordinates of magnetometer expressed
     * in Teslas (T).
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final double hardIronX, final double hardIronY, final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
        this.hardIronY = hardIronY;
        this.hardIronZ = hardIronZ;
    }

    /**
     * Sets known hard-iron coordinates.
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final MagneticFluxDensity hardIronX, final MagneticFluxDensity hardIronY,
            final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @return known hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA, hardIronX, hardIronY, hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(hardIronX, hardIronY, hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known hard-iron.
     *
     * @param hardIron hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIron(final MagneticFluxDensityTriad hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        hardIronX = convertMagneticFluxDensity(hardIron.getValueX(), hardIron.getUnit());
        hardIronY = convertMagneticFluxDensity(hardIron.getValueY(), hardIron.getUnit());
        hardIronZ = convertMagneticFluxDensity(hardIron.getValueZ(), hardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getHardIron(result);
        return result;
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = hardIronX;
        result[1] = hardIronY;
        result[2] = hardIronZ;
    }

    /**
     * Sets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param hardIron known hard-iron bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setHardIron(final double[] hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (hardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        hardIronX = hardIron[0];
        hardIronY = hardIron[1];
        hardIronZ = hardIron[2];
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @return hard-iron bias as a column matrix.
     */
    @Override
    public Matrix getHardIronMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getHardIronMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getHardIronMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, hardIronX);
        result.setElementAtIndex(1, hardIronY);
        result.setElementAtIndex(2, hardIronZ);
    }

    /**
     * Sets known hard-iron bias.
     *
     * @param hardIron magnetometer hard-iron bias to be set.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setHardIron(final Matrix hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (hardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || hardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        hardIronX = hardIron.getElementAtIndex(0);
        hardIronY = hardIron.getElementAtIndex(1);
        hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public Collection<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {

}

    /**
     * Gets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = biasY;
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = biasZ;
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasXAsAcceleration() {
        return new Acceleration(biasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasXAsAcceleration(final Acceleration result) {
        result.setValue(biasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final Acceleration biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAcceleration(biasX);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasYAsAcceleration() {
        return new Acceleration(biasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasYAsAcceleration(final Acceleration result) {
        result.setValue(biasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final Acceleration biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = convertAcceleration(biasY);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasZAsAcceleration() {
        return new Acceleration(biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasZAsAcceleration(final Acceleration result) {
        result.setValue(biasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets z-coordinate of known accelerometer bias to be used to find a solution.
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final Acceleration biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Sets known bias coordinates of accelerometer expressed in meters
     * per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @param biasY y-coordinate of known accelerometer bias.
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
        this.biasY = biasY;
        this.biasZ = biasZ;
    }

    /**
     * Sets known bias coordinates of accelerometer.
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @param biasY y-coordinate of known accelerometer bias.
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(
            final Acceleration biasX, final Acceleration biasY, final Acceleration biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAcceleration(biasX);
        this.biasY = convertAcceleration(biasY);
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @return known accelerometer bias.
     */
    @Override
    public AccelerationTriad getBiasAsTriad() {
        return new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getBiasAsTriad(final AccelerationTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known accelerometer bias.
     *
     * @param bias accelerometer bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBias(final AccelerationTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAcceleration(bias.getValueX(), bias.getUnit());
        biasY = convertAcceleration(bias.getValueY(), bias.getUnit());
        biasZ = convertAcceleration(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param bias known bias to be set
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (bias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        biasX = bias[0];
        biasY = bias[1];
        biasZ = bias[2];
    }

    /**
     * Gets known bias as a column matrix.
     *
     * @return known bias as a column matrix.
     */
    @Override
    public Matrix getBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, biasX);
        result.setElementAtIndex(1, biasY);
        result.setElementAtIndex(2, biasZ);
    }

    /**
     * Sets known bias as an array.
     *
     * @param bias bias to be set.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setBias(final Matrix bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (bias.getRows() != BodyKinematics.COMPONENTS || bias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        biasX = bias.getElementAtIndex(0);
        biasY = bias.getElementAtIndex(1);
        biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyKinematics> getMeasurements() {

}

    /**
     * Gets initial x-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return initial x-coordinate of accelerometer bias.
     */
    @Override
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return initial y-coordinate of accelerometer bias.
     */
    @Override
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return initial z-coordinate of accelerometer bias.
     */
    @Override
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of accelerometer bias to be used to find a solution.
     *
     * @return initial x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getInitialBiasXAsAcceleration() {
        return new Acceleration(initialBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial x-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasXAsAcceleration(final Acceleration result) {
        result.setValue(initialBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial x-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasX(final Acceleration initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAcceleration(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of accelerometer bias to be used to find a solution.
     *
     * @return initial y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getInitialBiasYAsAcceleration() {
        return new Acceleration(initialBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial y-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasYAsAcceleration(final Acceleration result) {
        result.setValue(initialBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial y-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasY(final Acceleration initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAcceleration(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of accelerometer bias to be used to find a solution.
     *
     * @return initial z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getInitialBiasZAsAcceleration() {
        return new Acceleration(initialBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial z-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasZAsAcceleration(final Acceleration result) {
        result.setValue(initialBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial z-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasZ(final Acceleration initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAcceleration(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of accelerometer used to find a solution
     * expressed in meters per squared second (m/s^2).
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(final double initialBiasX, final double initialBiasY, final double initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of accelerometer used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(final Acceleration initialBiasX, final Acceleration initialBiasY,
                               final Acceleration initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAcceleration(initialBiasX);
        this.initialBiasY = convertAcceleration(initialBiasY);
        this.initialBiasZ = convertAcceleration(initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of accelerometer used to find a solution.
     *
     * @return initial bias coordinates.
     */
    @Override
    public AccelerationTriad getInitialBiasAsTriad() {
        return new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND,
                initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of accelerometer used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialBiasAsTriad(final AccelerationTriad result) {
        result.setValueCoordinatesAndUnit(initialBiasX, initialBiasY, initialBiasZ,
                AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial bias coordinates of accelerometer used to find a solution.
     *
     * @param initialBias initial bias coordinates to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(final AccelerationTriad initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialBiasX = convertAcceleration(initialBias.getValueX(), initialBias.getUnit());
        initialBiasY = convertAcceleration(initialBias.getValueY(), initialBias.getUnit());
        initialBiasZ = convertAcceleration(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(final double initialSx, final double initialSy, final double initialSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial bias to be used to find a solution as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial bias to be used to find a solution as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial bias to be used to find a solution as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial bias to be used to find a solution as a column matrix.
     * Values are expressed in meters per squared second (m/s^2).
     *
     * @return initial bias to be used to find a solution as a column matrix.
     */
    @Override
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial bias to be used to find a solution as a column matrix.
     * Values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial bias to be used to find a solution as a column matrix with
     * values expressed in meters per squared second (m/s^2).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyKinematics> getMeasurements() {

}

    /**
     * Gets known x-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronX() {
        return hardIronX;
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronX known x-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final double hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
    }

    /**
     * Gets known y-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronY() {
        return hardIronY;
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronY known y-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final double hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = hardIronY;
    }

    /**
     * Gets known z-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronZ() {
        return hardIronZ;
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron bias.
     * This is expressed in meters Teslas (T).
     *
     * @param hardIronZ known z-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = hardIronZ;
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @return x coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron.
     *
     * @param hardIronX known x-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final MagneticFluxDensity hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @return y coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron.
     *
     * @param hardIronY known y-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final MagneticFluxDensity hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @return z coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron.
     *
     * @param hardIronZ known z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Sets known hard-iron bias coordinates of magnetometer expressed in
     * Teslas (T).
     *
     * @param hardIronX x-coordinate of magnetometer
     *                  known hard-iron bias.
     * @param hardIronY y-coordinate of magnetometer
     *                  known hard-iron bias.
     * @param hardIronZ z-coordinate of magnetometer
     *                  known hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final double hardIronX, final double hardIronY, final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
        this.hardIronY = hardIronY;
        this.hardIronZ = hardIronZ;
    }

    /**
     * Sets known hard-iron coordinates.
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final MagneticFluxDensity hardIronX, final MagneticFluxDensity hardIronY,
            final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @return known hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA, hardIronX, hardIronY, hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(hardIronX, hardIronY, hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known hard-iron.
     *
     * @param hardIron hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIron(final MagneticFluxDensityTriad hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        hardIronX = convertMagneticFluxDensity(hardIron.getValueX(), hardIron.getUnit());
        hardIronY = convertMagneticFluxDensity(hardIron.getValueY(), hardIron.getUnit());
        hardIronZ = convertMagneticFluxDensity(hardIron.getValueZ(), hardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getHardIron(result);
        return result;
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = hardIronX;
        result[1] = hardIronY;
        result[2] = hardIronZ;
    }

    /**
     * Sets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param hardIron known hard-iron.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setHardIron(final double[] hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (hardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        hardIronX = hardIron[0];
        hardIronY = hardIron[1];
        hardIronZ = hardIron[2];
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @return known hard-iron bias as a column matrix.
     */
    @Override
    public Matrix getHardIronMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getHardIronMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getHardIronMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, hardIronX);
        result.setElementAtIndex(1, hardIronY);
        result.setElementAtIndex(2, hardIronZ);
    }

    /**
     * Sets known hard-iron bias as a column matrix.
     *
     * @param hardIron known hard-iron bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setHardIron(final Matrix hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (hardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || hardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        hardIronX = hardIron.getElementAtIndex(0);
        hardIronY = hardIron.getElementAtIndex(1);
        hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

}

    /**
     * Gets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronX() {
        return initialHardIronX;
    }

    /**
     * Sets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final double initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
    }

    /**
     * Gets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronY() {
        return initialHardIronY;
    }

    /**
     * Sets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final double initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = initialHardIronY;
    }

    /**
     * Gets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronZ() {
        return initialHardIronZ;
    }

    /**
     * Sets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in meters Teslas (T).
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final double initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final MagneticFluxDensity initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final MagneticFluxDensity initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias coordinates of magnetometer used to find
     * a solution expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final double initialHardIronX, final double initialHardIronY, final double initialHardIronZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
        this.initialHardIronY = initialHardIronY;
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Sets initial hard iron coordinates of magnetometer used to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final MagneticFluxDensity initialHardIronX, final MagneticFluxDensity initialHardIronY,
            final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @return initial hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getInitialHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                initialHardIronX, initialHardIronY, initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(initialHardIronX, initialHardIronY, initialHardIronZ,
                MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial hard-iron used to find a solution.
     *
     * @param initialHardIron initial hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(final MagneticFluxDensityTriad initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialHardIronX = convertMagneticFluxDensity(initialHardIron.getValueX(), initialHardIron.getUnit());
        initialHardIronY = convertMagneticFluxDensity(initialHardIron.getValueY(), initialHardIron.getUnit());
        initialHardIronZ = convertMagneticFluxDensity(initialHardIron.getValueZ(), initialHardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getInitialHardIron(result);
        return result;
    }

    /**
     * Gets initial hard-iron  bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getInitialHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialHardIronX;
        result[1] = initialHardIronY;
        result[2] = initialHardIronZ;
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialHardIron(final double[] initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialHardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialHardIronX = initialHardIron[0];
        initialHardIronY = initialHardIron[1];
        initialHardIronZ = initialHardIron[2];
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @return initial hard-iron bias to be used to find a solution as a
     * column matrix.
     */
    @Override
    public Matrix getInitialHardIronAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getInitialHardIronAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialHardIronAsMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialHardIronX);
        result.setElementAtIndex(1, initialHardIronY);
        result.setElementAtIndex(2, initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as a column
     * matrix with values expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialHardIron(final Matrix initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialHardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || initialHardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialHardIronX = initialHardIron.getElementAtIndex(0);
        initialHardIronY = initialHardIron.getElementAtIndex(1);
        initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

}

    /**
     * Gets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronX() {
        return initialHardIronX;
    }

    /**
     * Sets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final double initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
    }

    /**
     * Gets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronY() {
        return initialHardIronY;
    }

    /**
     * Sets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final double initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = initialHardIronY;
    }

    /**
     * Gets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronZ() {
        return initialHardIronZ;
    }

    /**
     * Sets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in meters Teslas (T).
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final double initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final MagneticFluxDensity initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final MagneticFluxDensity initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias coordinates of magnetometer used to find
     * a solution expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final double initialHardIronX, final double initialHardIronY, final double initialHardIronZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
        this.initialHardIronY = initialHardIronY;
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Sets initial hard iron coordinates of magnetometer used to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final MagneticFluxDensity initialHardIronX, final MagneticFluxDensity initialHardIronY,
            final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @return initial hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getInitialHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                initialHardIronX, initialHardIronY, initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(initialHardIronX, initialHardIronY, initialHardIronZ,
                MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial hard-iron used to find a solution.
     *
     * @param initialHardIron initial hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(final MagneticFluxDensityTriad initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialHardIronX = convertMagneticFluxDensity(initialHardIron.getValueX(), initialHardIron.getUnit());
        initialHardIronY = convertMagneticFluxDensity(initialHardIron.getValueY(), initialHardIron.getUnit());
        initialHardIronZ = convertMagneticFluxDensity(initialHardIron.getValueZ(), initialHardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getInitialHardIron(result);
        return result;
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getInitialHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialHardIronX;
        result[1] = initialHardIronY;
        result[2] = initialHardIronZ;
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialHardIron(final double[] initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialHardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialHardIronX = initialHardIron[0];
        initialHardIronY = initialHardIron[1];
        initialHardIronZ = initialHardIron[2];
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @return initial hard-iron bias to be used to find a solution as a
     * column matrix.
     */
    @Override
    public Matrix getInitialHardIronAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getInitialHardIronAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialHardIronAsMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialHardIronX);
        result.setElementAtIndex(1, initialHardIronY);
        result.setElementAtIndex(2, initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as a column
     * matrix with values expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialHardIron(final Matrix initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialHardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || initialHardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialHardIronX = initialHardIron.getElementAtIndex(0);
        initialHardIronY = initialHardIron.getElementAtIndex(1);
        initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a list of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public List<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {

}

    /**
     * Gets x-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return x-coordinate of known magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronX() {
        return hardIronX;
    }

    /**
     * Sets x-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronX x coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final double hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
    }

    /**
     * Gets y-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return y-coordinate of known magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronY() {
        return hardIronY;
    }

    /**
     * Sets y-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronY y coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final double hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = hardIronY;
    }

    /**
     * Gets z-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return z-coordinate of known magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronZ() {
        return hardIronZ;
    }

    /**
     * Sets z-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronZ z coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = hardIronZ;
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @return x coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron.
     *
     * @param hardIronX known x-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final MagneticFluxDensity hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @return y coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron.
     *
     * @param hardIronY known y-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final MagneticFluxDensity hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @return z coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron.
     *
     * @param hardIronZ known z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Sets known hard-iron bias coordinates of magnetometer expressed
     * in Teslas (T).
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final double hardIronX, final double hardIronY, final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
        this.hardIronY = hardIronY;
        this.hardIronZ = hardIronZ;
    }

    /**
     * Sets known hard-iron coordinates.
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final MagneticFluxDensity hardIronX, final MagneticFluxDensity hardIronY,
            final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @return known hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA, hardIronX, hardIronY, hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(hardIronX, hardIronY, hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known hard-iron.
     *
     * @param hardIron hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIron(final MagneticFluxDensityTriad hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        hardIronX = convertMagneticFluxDensity(hardIron.getValueX(), hardIron.getUnit());
        hardIronY = convertMagneticFluxDensity(hardIron.getValueY(), hardIron.getUnit());
        hardIronZ = convertMagneticFluxDensity(hardIron.getValueZ(), hardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getHardIron(result);
        return result;
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = hardIronX;
        result[1] = hardIronY;
        result[2] = hardIronZ;
    }

    /**
     * Sets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param hardIron known hard-iron bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setHardIron(final double[] hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (hardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        hardIronX = hardIron[0];
        hardIronY = hardIron[1];
        hardIronZ = hardIron[2];
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @return hard-iron bias as a column matrix.
     */
    @Override
    public Matrix getHardIronMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getHardIronMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getHardIronMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, hardIronX);
        result.setElementAtIndex(1, hardIronY);
        result.setElementAtIndex(2, hardIronZ);
    }

    /**
     * Sets known hard-iron bias.
     *
     * @param hardIron magnetometer hard-iron bias to be set.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setHardIron(final Matrix hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (hardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || hardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        hardIronX = hardIron.getElementAtIndex(0);
        hardIronY = hardIron.getElementAtIndex(1);
        hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a list of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public List<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {

}
    }

    /**
     * Gets known x-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronX() {
        return hardIronX;
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronX known x-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final double hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
    }

    /**
     * Gets known y-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronY() {
        return hardIronY;
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronY known y-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final double hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = hardIronY;
    }

    /**
     * Gets known z-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronZ() {
        return hardIronZ;
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron bias.
     * This is expressed in meters Teslas (T).
     *
     * @param hardIronZ known z-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = hardIronZ;
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @return x coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron.
     *
     * @param hardIronX known x-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final MagneticFluxDensity hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @return y coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron.
     *
     * @param hardIronY known y-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final MagneticFluxDensity hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @return z coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron.
     *
     * @param hardIronZ known z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Sets known hard-iron bias coordinates of magnetometer expressed in
     * Teslas (T).
     *
     * @param hardIronX x-coordinate of magnetometer
     *                  known hard-iron bias.
     * @param hardIronY y-coordinate of magnetometer
     *                  known hard-iron bias.
     * @param hardIronZ z-coordinate of magnetometer
     *                  known hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final double hardIronX, final double hardIronY, final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
        this.hardIronY = hardIronY;
        this.hardIronZ = hardIronZ;
    }

    /**
     * Sets known hard-iron coordinates.
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final MagneticFluxDensity hardIronX, final MagneticFluxDensity hardIronY,
            final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @return known hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA, hardIronX, hardIronY, hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(hardIronX, hardIronY, hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known hard-iron.
     *
     * @param hardIron hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIron(final MagneticFluxDensityTriad hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        hardIronX = convertMagneticFluxDensity(hardIron.getValueX(), hardIron.getUnit());
        hardIronY = convertMagneticFluxDensity(hardIron.getValueY(), hardIron.getUnit());
        hardIronZ = convertMagneticFluxDensity(hardIron.getValueZ(), hardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getHardIron(result);
        return result;
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = hardIronX;
        result[1] = hardIronY;
        result[2] = hardIronZ;
    }

    /**
     * Sets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param hardIron known hard-iron.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setHardIron(final double[] hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (hardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        hardIronX = hardIron[0];
        hardIronY = hardIron[1];
        hardIronZ = hardIron[2];
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @return known hard-iron bias as a column matrix.
     */
    @Override
    public Matrix getHardIronMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getHardIronMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getHardIronMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, hardIronX);
        result.setElementAtIndex(1, hardIronY);
        result.setElementAtIndex(2, hardIronZ);
    }

    /**
     * Sets known hard-iron bias as a column matrix.
     *
     * @param hardIron known hard-iron bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setHardIron(final Matrix hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (hardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || hardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        hardIronX = hardIron.getElementAtIndex(0);
        hardIronY = hardIron.getElementAtIndex(1);
        hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

}
    }

    /**
     * Gets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronX() {
        return initialHardIronX;
    }

    /**
     * Sets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final double initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
    }

    /**
     * Gets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronY() {
        return initialHardIronY;
    }

    /**
     * Sets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final double initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = initialHardIronY;
    }

    /**
     * Gets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronZ() {
        return initialHardIronZ;
    }

    /**
     * Sets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in meters Teslas (T).
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final double initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final MagneticFluxDensity initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final MagneticFluxDensity initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias coordinates of magnetometer used to find
     * a solution expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final double initialHardIronX, final double initialHardIronY, final double initialHardIronZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
        this.initialHardIronY = initialHardIronY;
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Sets initial hard iron coordinates of magnetometer used to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final MagneticFluxDensity initialHardIronX, final MagneticFluxDensity initialHardIronY,
            final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @return initial hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getInitialHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                initialHardIronX, initialHardIronY, initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(initialHardIronX, initialHardIronY, initialHardIronZ,
                MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial hard-iron used to find a solution.
     *
     * @param initialHardIron initial hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(final MagneticFluxDensityTriad initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialHardIronX = convertMagneticFluxDensity(initialHardIron.getValueX(), initialHardIron.getUnit());
        initialHardIronY = convertMagneticFluxDensity(initialHardIron.getValueY(), initialHardIron.getUnit());
        initialHardIronZ = convertMagneticFluxDensity(initialHardIron.getValueZ(), initialHardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getInitialHardIron(result);
        return result;
    }

    /**
     * Gets initial hard-iron  bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getInitialHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialHardIronX;
        result[1] = initialHardIronY;
        result[2] = initialHardIronZ;
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialHardIron(final double[] initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialHardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialHardIronX = initialHardIron[0];
        initialHardIronY = initialHardIron[1];
        initialHardIronZ = initialHardIron[2];
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @return initial hard-iron bias to be used to find a solution as a
     * column matrix.
     */
    @Override
    public Matrix getInitialHardIronAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getInitialHardIronAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialHardIronAsMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialHardIronX);
        result.setElementAtIndex(1, initialHardIronY);
        result.setElementAtIndex(2, initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as a column
     * matrix with values expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialHardIron(final Matrix initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialHardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || initialHardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialHardIronX = initialHardIron.getElementAtIndex(0);
        initialHardIronY = initialHardIron.getElementAtIndex(1);
        initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

}

    /**
     * Gets known x-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronX() {
        return hardIronX;
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronX known x-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final double hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
    }

    /**
     * Gets known y-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronY() {
        return hardIronY;
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronY known y-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final double hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = hardIronY;
    }

    /**
     * Gets known z-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronZ() {
        return hardIronZ;
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron bias.
     * This is expressed in meters Teslas (T).
     *
     * @param hardIronZ known z-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = hardIronZ;
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @return x coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron.
     *
     * @param hardIronX known x-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final MagneticFluxDensity hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @return y coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron.
     *
     * @param hardIronY known y-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final MagneticFluxDensity hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @return z coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron.
     *
     * @param hardIronZ known z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Sets known hard-iron bias coordinates of magnetometer expressed in
     * Teslas (T).
     *
     * @param hardIronX x-coordinate of magnetometer
     *                  known hard-iron bias.
     * @param hardIronY y-coordinate of magnetometer
     *                  known hard-iron bias.
     * @param hardIronZ z-coordinate of magnetometer
     *                  known hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final double hardIronX, final double hardIronY, final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
        this.hardIronY = hardIronY;
        this.hardIronZ = hardIronZ;
    }

    /**
     * Sets known hard-iron coordinates.
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final MagneticFluxDensity hardIronX, final MagneticFluxDensity hardIronY,
            final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @return known hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA, hardIronX, hardIronY, hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(hardIronX, hardIronY, hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known hard-iron.
     *
     * @param hardIron hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIron(final MagneticFluxDensityTriad hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        hardIronX = convertMagneticFluxDensity(hardIron.getValueX(), hardIron.getUnit());
        hardIronY = convertMagneticFluxDensity(hardIron.getValueY(), hardIron.getUnit());
        hardIronZ = convertMagneticFluxDensity(hardIron.getValueZ(), hardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getHardIron(result);
        return result;
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = hardIronX;
        result[1] = hardIronY;
        result[2] = hardIronZ;
    }

    /**
     * Sets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param hardIron known hard-iron.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setHardIron(final double[] hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (hardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        hardIronX = hardIron[0];
        hardIronY = hardIron[1];
        hardIronZ = hardIron[2];
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @return known hard-iron bias as a column matrix.
     */
    @Override
    public Matrix getHardIronMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getHardIronMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getHardIronMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, hardIronX);
        result.setElementAtIndex(1, hardIronY);
        result.setElementAtIndex(2, hardIronZ);
    }

    /**
     * Sets known hard-iron bias as a column matrix.
     *
     * @param hardIron known hard-iron bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setHardIron(final Matrix hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (hardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || hardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        hardIronX = hardIron.getElementAtIndex(0);
        hardIronY = hardIron.getElementAtIndex(1);
        hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

}

    /**
     * Gets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronX() {
        return initialHardIronX;
    }

    /**
     * Sets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final double initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
    }

    /**
     * Gets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronY() {
        return initialHardIronY;
    }

    /**
     * Sets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final double initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = initialHardIronY;
    }

    /**
     * Gets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronZ() {
        return initialHardIronZ;
    }

    /**
     * Sets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in meters Teslas (T).
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final double initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final MagneticFluxDensity initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final MagneticFluxDensity initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias coordinates of magnetometer used to find
     * a solution expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final double initialHardIronX, final double initialHardIronY, final double initialHardIronZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
        this.initialHardIronY = initialHardIronY;
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Sets initial hard iron coordinates of magnetometer used to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final MagneticFluxDensity initialHardIronX, final MagneticFluxDensity initialHardIronY,
            final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @return initial hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getInitialHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                initialHardIronX, initialHardIronY, initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(initialHardIronX, initialHardIronY, initialHardIronZ,
                MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial hard-iron used to find a solution.
     *
     * @param initialHardIron initial hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(final MagneticFluxDensityTriad initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialHardIronX = convertMagneticFluxDensity(initialHardIron.getValueX(), initialHardIron.getUnit());
        initialHardIronY = convertMagneticFluxDensity(initialHardIron.getValueY(), initialHardIron.getUnit());
        initialHardIronZ = convertMagneticFluxDensity(initialHardIron.getValueZ(), initialHardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getInitialHardIron(result);
        return result;
    }

    /**
     * Gets initial hard-iron  bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getInitialHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialHardIronX;
        result[1] = initialHardIronY;
        result[2] = initialHardIronZ;
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialHardIron(final double[] initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialHardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialHardIronX = initialHardIron[0];
        initialHardIronY = initialHardIron[1];
        initialHardIronZ = initialHardIron[2];
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @return initial hard-iron bias to be used to find a solution as a
     * column matrix.
     */
    @Override
    public Matrix getInitialHardIronAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getInitialHardIronAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialHardIronAsMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialHardIronX);
        result.setElementAtIndex(1, initialHardIronY);
        result.setElementAtIndex(2, initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as a column
     * matrix with values expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialHardIron(final Matrix initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialHardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || initialHardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialHardIronX = initialHardIron.getElementAtIndex(0);
        initialHardIronY = initialHardIron.getElementAtIndex(1);
        initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

}

    /**
     * Gets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronX() {
        return initialHardIronX;
    }

    /**
     * Sets initial x-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final double initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
    }

    /**
     * Gets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronY() {
        return initialHardIronY;
    }

    /**
     * Sets initial y-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final double initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = initialHardIronY;
    }

    /**
     * Gets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in Teslas (T).
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getInitialHardIronZ() {
        return initialHardIronZ;
    }

    /**
     * Sets initial z-coordinate of magnetometer hard-iron bias to be used
     * to find a solution.
     * This is expressed in meters Teslas (T).
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final double initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial x-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronX(final MagneticFluxDensity initialHardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial y-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronY(final MagneticFluxDensity initialHardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @return initial z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public MagneticFluxDensity getInitialHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(initialHardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(initialHardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial z-coordinate of magnetometer hard iron bias to be used
     * to find a solution.
     *
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIronZ(final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias coordinates of magnetometer used to find
     * a solution expressed in Teslas (T).
     *
     * @param initialHardIronX initial x-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronY initial y-coordinate of magnetometer
     *                         hard-iron bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer
     *                         hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final double initialHardIronX, final double initialHardIronY, final double initialHardIronZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialHardIronX = initialHardIronX;
        this.initialHardIronY = initialHardIronY;
        this.initialHardIronZ = initialHardIronZ;
    }

    /**
     * Sets initial hard iron coordinates of magnetometer used to find a solution.
     *
     * @param initialHardIronX initial x-coordinate of magnetometer bias.
     * @param initialHardIronY initial y-coordinate of magnetometer bias.
     * @param initialHardIronZ initial z-coordinate of magnetometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(
            final MagneticFluxDensity initialHardIronX, final MagneticFluxDensity initialHardIronY,
            final MagneticFluxDensity initialHardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.initialHardIronX = convertMagneticFluxDensity(initialHardIronX);
        this.initialHardIronY = convertMagneticFluxDensity(initialHardIronY);
        this.initialHardIronZ = convertMagneticFluxDensity(initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @return initial hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getInitialHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                initialHardIronX, initialHardIronY, initialHardIronZ);
    }

    /**
     * Gets initial hard-iron used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(initialHardIronX, initialHardIronY, initialHardIronZ,
                MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets initial hard-iron used to find a solution.
     *
     * @param initialHardIron initial hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialHardIron(final MagneticFluxDensityTriad initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialHardIronX = convertMagneticFluxDensity(initialHardIron.getValueX(), initialHardIron.getUnit());
        initialHardIronY = convertMagneticFluxDensity(initialHardIron.getValueY(), initialHardIron.getUnit());
        initialHardIronZ = convertMagneticFluxDensity(initialHardIron.getValueZ(), initialHardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getInitialHardIron(result);
        return result;
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getInitialHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialHardIronX;
        result[1] = initialHardIronY;
        result[2] = initialHardIronZ;
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialHardIron(final double[] initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialHardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialHardIronX = initialHardIron[0];
        initialHardIronY = initialHardIron[1];
        initialHardIronZ = initialHardIron[2];
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @return initial hard-iron bias to be used to find a solution as a
     * column matrix.
     */
    @Override
    public Matrix getInitialHardIronAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getInitialHardIronAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial hard-iron bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialHardIronAsMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialHardIronX);
        result.setElementAtIndex(1, initialHardIronY);
        result.setElementAtIndex(2, initialHardIronZ);
    }

    /**
     * Sets initial hard-iron bias to be used to find a solution as a column
     * matrix with values expressed in Teslas (T).
     *
     * @param initialHardIron initial hard-iron bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialHardIron(final Matrix initialHardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialHardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || initialHardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialHardIronX = initialHardIron.getElementAtIndex(0);
        initialHardIronY = initialHardIron.getElementAtIndex(1);
        initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public Collection<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {

}

    /**
     * Gets x-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return x-coordinate of known magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronX() {
        return hardIronX;
    }

    /**
     * Sets x-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronX x coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final double hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
    }

    /**
     * Gets y-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return y-coordinate of known magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronY() {
        return hardIronY;
    }

    /**
     * Sets y-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronY y coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final double hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = hardIronY;
    }

    /**
     * Gets z-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return z-coordinate of known magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronZ() {
        return hardIronZ;
    }

    /**
     * Sets z-coordinate of known magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronZ z coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = hardIronZ;
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @return x coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron.
     *
     * @param hardIronX known x-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final MagneticFluxDensity hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @return y coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron.
     *
     * @param hardIronY known y-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final MagneticFluxDensity hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @return z coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron.
     *
     * @param hardIronZ known z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Sets known hard-iron bias coordinates of magnetometer expressed
     * in Teslas (T).
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final double hardIronX, final double hardIronY, final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
        this.hardIronY = hardIronY;
        this.hardIronZ = hardIronZ;
    }

    /**
     * Sets known hard-iron coordinates.
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final MagneticFluxDensity hardIronX, final MagneticFluxDensity hardIronY,
            final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @return known hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA, hardIronX, hardIronY, hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(hardIronX, hardIronY, hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known hard-iron.
     *
     * @param hardIron hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIron(final MagneticFluxDensityTriad hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        hardIronX = convertMagneticFluxDensity(hardIron.getValueX(), hardIron.getUnit());
        hardIronY = convertMagneticFluxDensity(hardIron.getValueY(), hardIron.getUnit());
        hardIronZ = convertMagneticFluxDensity(hardIron.getValueZ(), hardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getHardIron(result);
        return result;
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = hardIronX;
        result[1] = hardIronY;
        result[2] = hardIronZ;
    }

    /**
     * Sets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param hardIron known hard-iron bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setHardIron(final double[] hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (hardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        hardIronX = hardIron[0];
        hardIronY = hardIron[1];
        hardIronZ = hardIron[2];
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @return hard-iron bias as a column matrix.
     */
    @Override
    public Matrix getHardIronMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getHardIronMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getHardIronMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, hardIronX);
        result.setElementAtIndex(1, hardIronY);
        result.setElementAtIndex(2, hardIronZ);
    }

    /**
     * Sets known hard-iron bias.
     *
     * @param hardIron magnetometer hard-iron bias to be set.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setHardIron(final Matrix hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (hardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || hardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        hardIronX = hardIron.getElementAtIndex(0);
        hardIronY = hardIron.getElementAtIndex(1);
        hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public Collection<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {

}

    /**
     * Gets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = biasY;
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = biasZ;
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasXAsAcceleration() {
        return new Acceleration(biasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasXAsAcceleration(final Acceleration result) {
        result.setValue(biasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final Acceleration biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAcceleration(biasX);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasYAsAcceleration() {
        return new Acceleration(biasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasYAsAcceleration(final Acceleration result) {
        result.setValue(biasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final Acceleration biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = convertAcceleration(biasY);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasZAsAcceleration() {
        return new Acceleration(biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasZAsAcceleration(final Acceleration result) {
        result.setValue(biasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets z-coordinate of known accelerometer bias to be used to find a solution.
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final Acceleration biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Sets known bias coordinates of accelerometer expressed in meters
     * per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @param biasY y-coordinate of known accelerometer bias.
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
        this.biasY = biasY;
        this.biasZ = biasZ;
    }

    /**
     * Sets known bias coordinates of accelerometer.
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @param biasY y-coordinate of known accelerometer bias.
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(
            final Acceleration biasX, final Acceleration biasY, final Acceleration biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAcceleration(biasX);
        this.biasY = convertAcceleration(biasY);
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @return known accelerometer bias.
     */
    @Override
    public AccelerationTriad getBiasAsTriad() {
        return new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getBiasAsTriad(final AccelerationTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known accelerometer bias.
     *
     * @param bias accelerometer bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBias(final AccelerationTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAcceleration(bias.getValueX(), bias.getUnit());
        biasY = convertAcceleration(bias.getValueY(), bias.getUnit());
        biasZ = convertAcceleration(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param bias known bias to be set
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (bias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        biasX = bias[0];
        biasY = bias[1];
        biasZ = bias[2];
    }

    /**
     * Gets known bias as a column matrix.
     *
     * @return known bias as a column matrix.
     */
    @Override
    public Matrix getBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, biasX);
        result.setElementAtIndex(1, biasY);
        result.setElementAtIndex(2, biasZ);
    }

    /**
     * Sets known bias as an array.
     *
     * @param bias bias to be set.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setBias(final Matrix bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (bias.getRows() != BodyKinematics.COMPONENTS || bias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        biasX = bias.getElementAtIndex(0);
        biasY = bias.getElementAtIndex(1);
        biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

this(convertAcceleration(groundTruthGravityNorm), measurements, commonAxisUsed, initialBias, initialMa,
                listener);
    }

    /**
     * Gets initial x-coordinate of accelerometer bias to be used to find a solutions.
     * This is expressed in meters per squared second (m/s^2) and only taken into
     * account if non-linear preliminary solutions are used.
     *
     * @return initial x-coordinate of accelerometer bias.
     */
    @Override
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2) and only taken into
     * account if non-linear preliminary solutions are used.
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2) and only taken into
     * account if non-linear preliminary solutions are used.
     *
     * @return initial y-coordinate of accelerometer bias.
     */
    @Override
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2) and only taken into
     * account if non-linear preliminary solutions are used.
     *
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2) and only taken into
     * account if non-linear preliminary solutions are used.
     *
     * @return initial z-coordinate of accelerometer bias.
     */
    @Override
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2) and only taken into
     * account if non-linear preliminary solutions are used.
     *
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of accelerometer bias to be used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getInitialBiasXAsAcceleration() {
        return new Acceleration(initialBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial x-coordinate of accelerometer bias to be used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasXAsAcceleration(final Acceleration result) {
        result.setValue(initialBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial x-coordinate of accelerometer bias to be used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasX(final Acceleration initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAcceleration(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of accelerometer bias to be used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getInitialBiasYAsAcceleration() {
        return new Acceleration(initialBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial y-coordinate of accelerometer bias to be used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasYAsAcceleration(final Acceleration result) {
        result.setValue(initialBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial y-coordinate of accelerometer bias to be used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasY(final Acceleration initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAcceleration(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of accelerometer bias to be used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getInitialBiasZAsAcceleration() {
        return new Acceleration(initialBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial z-coordinate of accelerometer bias to be used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasZAsAcceleration(final Acceleration result) {
        result.setValue(initialBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial z-coordinate of accelerometer bias to be used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasZ(final Acceleration initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAcceleration(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of accelerometer used to find a solution
     * expressed in meters per squared second (m/s^2).
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(final double initialBiasX, final double initialBiasY, final double initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of accelerometer used to find a solution.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(
            final Acceleration initialBiasX, final Acceleration initialBiasY, final Acceleration initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAcceleration(initialBiasX);
        this.initialBiasY = convertAcceleration(initialBiasY);
        this.initialBiasZ = convertAcceleration(initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of accelerometer used to find a solution.
     *
     * @return initial bias coordinates.
     */
    @Override
    public AccelerationTriad getInitialBiasAsTriad() {
        return new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND,
                initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of accelerometer used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialBiasAsTriad(final AccelerationTriad result) {
        result.setValueCoordinatesAndUnit(initialBiasX, initialBiasY, initialBiasZ,
                AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial bias coordinates of accelerometer used to find a solution.
     *
     * @param initialBias initial bias coordinates to be set.
     */
    @Override
    public void setInitialBias(final AccelerationTriad initialBias) {
        initialBiasX = convertAcceleration(initialBias.getValueX(), initialBias.getUnit());
        initialBiasY = convertAcceleration(initialBias.getValueY(), initialBias.getUnit());
        initialBiasZ = convertAcceleration(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(final double initialSx, final double initialSy, final double initialSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial bias to be used to find a solution as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial bias to be used to find a solution as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial bias to be used to find a solution as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial bias to be used to find a solution as a column matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     * Values are expressed in meters per squared second (m/s^2).
     *
     * @return initial bias to be used to find a solution as a column matrix.
     */
    @Override
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial bias to be used to find a solution as a column matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     * Values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial bias to be used to find a solution as an array.
     * This is only taken into account if non-linear preliminary solutions are used.
     * Values are expressed in meters per squared second (m/s^2).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets ground truth gravity norm to be expected at location where measurements have been made,
     * expressed in meter per squared second (m/s^2).
     *
     * @return ground truth gravity norm or null.
     */
    public Double getGroundTruthGravityNorm() {

&& groundTruthGravityNorm != null;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return array containing x,y,z components of estimated accelerometer biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where estimated accelerometer biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return column matrix containing x,y,z components of estimated accelerometer
     * biases
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFx() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return y coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFy() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return z coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFz() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated accelerometer bias.
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Acceleration getEstimatedBiasFxAsAcceleration() {
        return estimatedBiases != null
                ? new Acceleration(estimatedBiases[0], AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasFxAsAcceleration(final Acceleration result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated accelerometer bias.
     *
     * @return y coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Acceleration getEstimatedBiasFyAsAcceleration() {
        return estimatedBiases != null
                ? new Acceleration(estimatedBiases[1], AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasFyAsAcceleration(final Acceleration result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated accelerometer bias.
     *
     * @return z coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Acceleration getEstimatedBiasFzAsAcceleration() {
        return estimatedBiases != null
                ? new Acceleration(estimatedBiases[2], AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasFzAsAcceleration(final Acceleration result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated accelerometer bias.
     *
     * @return estimated accelerometer bias or null if not available.
     */
    @Override
    public AccelerationTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated accelerometer bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AccelerationTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(estimatedBiases[0], estimatedBiases[1], estimatedBiases[2],
                    AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {
        return estimatedMa;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration solution.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bx, by, bz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy.
     * This is only available when result has been refined and covariance
     * is kept.
     *
     * @return estimated covariance matrix for estimated position.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets variance of estimated x coordinate of accelerometer bias expressed in (m^2/s^4).
     *
     * @return variance of estimated x coordinate of accelerometer bias or null if not available.
     */
    public Double getEstimatedBiasFxVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of accelerometer bias expressed in
     * meters per squared second (m/s^2).
     *
     * @return standard deviation of estimated x coordinate of accelerometer bias or null if not
     * available.
     */
    public Double getEstimatedBiasFxStandardDeviation() {
        final var variance = getEstimatedBiasFxVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of accelerometer bias.
     *
     * @return standard deviation of estimated x coordinate of accelerometer bias or null if not
     * available.
     */
    public Acceleration getEstimatedBiasFxStandardDeviationAsAcceleration() {
        return estimatedCovariance != null
                ? new Acceleration(getEstimatedBiasFxStandardDeviation(), AccelerationUnit.METERS_PER_SQUARED_SECOND) :
                null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of accelerometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasFxStandardDeviationAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasFxStandardDeviation());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of accelerometer bias expressed in (m^2/s^4).
     *
     * @return variance of estimated y coordinate of accelerometer bias or null if not available.
     */
    public Double getEstimatedBiasFyVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of accelerometer bias expressed in
     * meters per squared second (m/s^2).
     *
     * @return standard deviation of estimated y coordinate of accelerometer bias or null if not
     * available.
     */
    public Double getEstimatedBiasFyStandardDeviation() {
        final var variance = getEstimatedBiasFyVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of accelerometer bias.
     *
     * @return standard deviation of estimated y coordinate of accelerometer bias or null if not
     * available.
     */
    public Acceleration getEstimatedBiasFyStandardDeviationAsAcceleration() {
        return estimatedCovariance != null
                ? new Acceleration(getEstimatedBiasFyStandardDeviation(), AccelerationUnit.METERS_PER_SQUARED_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of accelerometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasFyStandardDeviationAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasFyStandardDeviation());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of accelerometer bias expressed in (m^2/s^4).
     *
     * @return variance of estimated z coordinate of accelerometer bias or null if not available.
     */
    public Double getEstimatedBiasFzVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of accelerometer bias expressed in
     * meters per squared second (m/s^2).
     *
     * @return standard deviation of estimated z coordinate of accelerometer bias or null if not
     * available.
     */
    public Double getEstimatedBiasFzStandardDeviation() {
        final var variance = getEstimatedBiasFzVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of accelerometer bias.
     *
     * @return standard deviation of estimated z coordinate of accelerometer bias or null if not
     * available.
     */
    public Acceleration getEstimatedBiasFzStandardDeviationAsAcceleration() {
        return estimatedCovariance != null
                ? new Acceleration(getEstimatedBiasFzStandardDeviation(), AccelerationUnit.METERS_PER_SQUARED_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of accelerometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasFzStandardDeviationAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasFzStandardDeviation());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated accelerometer bias coordinates.
     *
     * @return standard deviation of estimated accelerometer bias coordinates.
     */
    public AccelerationTriad getEstimatedBiasStandardDeviation() {
        return estimatedCovariance != null
                ? new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND,
                getEstimatedBiasFxStandardDeviation(),
                getEstimatedBiasFyStandardDeviation(),
                getEstimatedBiasFzStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated accelerometer bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of accelerometer bias was available, false
     * otherwise.
     */
    public boolean getEstimatedBiasStandardDeviation(final AccelerationTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedBiasFxStandardDeviation(),
                    getEstimatedBiasFyStandardDeviation(),
                    getEstimatedBiasFzStandardDeviation(),
                    AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of accelerometer bias coordinates expressed
     * in meters per squared second (m/s^2).
     *
     * @return average of estimated standard deviation of accelerometer bias coordinates or null
     * if not available.
     */
    public Double getEstimatedBiasStandardDeviationAverage() {
        return estimatedCovariance != null ? (getEstimatedBiasFxStandardDeviation()
                + getEstimatedBiasFyStandardDeviation() + getEstimatedBiasFzStandardDeviation()) / 3.0 : null;
    }

    /**
     * Gets average of estimated standard deviation of accelerometer bias coordinates.
     *
     * @return average of estimated standard deviation of accelerometer bias coordinates or null.
     */
    public Acceleration getEstimatedBiasStandardDeviationAverageAsAcceleration() {
        return estimatedCovariance != null
                ? new Acceleration(getEstimatedBiasStandardDeviationAverage(),
                AccelerationUnit.METERS_PER_SQUARED_SECOND)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of accelerometer bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of accelerometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationAverageAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationAverage());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of accelerometer bias expressed in
     * meters per squared second (m/s^2).
     * This can be used as the initial accelerometer bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of accelerometer bias or null
     * if not available.
     */
    @Override
    public Double getEstimatedBiasStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedBiasFxVariance() + getEstimatedBiasFyVariance() + getEstimatedBiasFzVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of accelerometer bias.
     * This can be used as the initial accelerometer bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of accelerometer bias or null
     * if not available.
     */
    public Acceleration getEstimatedBiasStandardDeviationNormAsAcceleration() {
        return estimatedCovariance != null
                ? new Acceleration(getEstimatedBiasStandardDeviationNorm(), AccelerationUnit.METERS_PER_SQUARED_SECOND)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of accelerometer bias coordinates.
     * This can be used as the initial accelerometer bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of accelerometer bias is
     * available, false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationNormAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationNorm());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurements()}.
     *
     * @return size of subsets to be checked during robust estimation.
     */
    public int getPreliminarySubsetSize() {
        return preliminarySubsetSize;
    }

    /**
     * Sets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurements()}.
     *
     * @param preliminarySubsetSize size of subsets to be checked during robust estimation.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is less than {@link #getMinimumRequiredMeasurements()}.
     */
    public void setPreliminarySubsetSize(final int preliminarySubsetSize) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (preliminarySubsetSize < getMinimumRequiredMeasurements()) {
            throw new IllegalArgumentException();
        }

        this.preliminarySubsetSize = preliminarySubsetSize;
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    public abstract RobustEstimatorMethod getMethod();

    /**
     * Creates a robust accelerometer calibrator.
     *
     * @param method robust estimator method.
     * @return a robust accelerometer calibrator.
     */
    public static RobustKnownGravityNormAccelerometerCalibrator create(

}

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @return array containing x,y,z components of estimated magnetometer
     * hard-iron biases.
     */
    @Override
    public double[] getEstimatedHardIron() {
        return estimatedHardIron;
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where estimated magnetometer biases will be
     *               stored.
     * @return true if result instance was updated, false otherwise (when
     * estimation is not yet available).
     */
    @Override
    public boolean getEstimatedHardIron(final double[] result) {
        if (estimatedHardIron != null) {
            System.arraycopy(estimatedHardIron, 0, result, 0, estimatedHardIron.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @return column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases.
     */
    @Override
    public Matrix getEstimatedHardIronAsMatrix() {
        return estimatedHardIron != null ? Matrix.newFromArray(estimatedHardIron) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedHardIronAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedHardIron != null) {
            result.fromArray(estimatedHardIron);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return x coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronX() {
        return estimatedHardIron != null ? estimatedHardIron[0] : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return y coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronY() {
        return estimatedHardIron != null ? estimatedHardIron[1] : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return z coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronZ() {
        return estimatedHardIron != null ? estimatedHardIron[2] : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @return x coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronXAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[0], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[0]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @return y coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronYAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[1], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[1]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @return z coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronZAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[2], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[2]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @return estimated magnetometer bias or null if not available.
     */
    @Override
    public MagneticFluxDensityTriad getEstimatedHardIronAsTriad() {
        return estimatedHardIron != null
                ? new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2])
                : null;
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronAsTriad(final MagneticFluxDensityTriad result) {
        if (estimatedHardIron != null) {
            result.setValueCoordinatesAndUnit(estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2],
                    MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bx, by, bz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy.
     *
     * @return estimated covariance matrix for estimated calibration parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets variance of estimated x coordinate of magnetometer bias expressed in
     * squared Teslas (T^2).
     *
     * @return variance of estimated x coordinate of magnetometer bias or null if
     * not available.
     */
    public Double getEstimatedHardIronXVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of magnetometer bias
     * expressed in Teslas (T).
     *
     * @return standard deviation of estimated x coordinate of magnetometer bias
     * or null if not available.
     */
    public Double getEstimatedHardIronXStandardDeviation() {
        final var variance = getEstimatedHardIronXVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of magnetometer bias.
     *
     * @return standard deviation of estimated x coordinate of magnetometer bias
     * or null if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronXStandardDeviationAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronXStandardDeviation(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of
     * magnetometer bias is available, false otherwise.
     */
    public boolean getEstimatedHardIronXStandardDeviationAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronXStandardDeviation());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of magnetometer bias expressed in
     * squared Teslas (T^2).
     *
     * @return variance of estimated y coordinate of magnetometer bias or null if
     * not available.
     */
    public Double getEstimatedHardIronYVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of magnetometer bias
     * expressed in Teslas (T).
     *
     * @return standard deviation of estimated y coordinate of magnetometer bias
     * or null if not available.
     */
    public Double getEstimatedHardIronYStandardDeviation() {
        final var variance = getEstimatedHardIronYVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of magnetometer bias.
     *
     * @return standard deviation of estimated y coordinate of magnetometer bias
     * or null if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronYStandardDeviationAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronYStandardDeviation(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of
     * magnetometer bias is available, false otherwise.
     */
    public boolean getEstimatedHardIronYStandardDeviationAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronYStandardDeviation());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of magnetometer bias expressed in
     * squared Teslas (T^2).
     *
     * @return variance of estimated z coordinate of magnetometer bias or null if
     * not available.
     */
    public Double getEstimatedHardIronZVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of magnetometer bias
     * expressed in Teslas (T).
     *
     * @return standard deviation of estimated z coordinate of magnetometer bias
     * or null if not available.
     */
    public Double getEstimatedHardIronZStandardDeviation() {
        final var variance = getEstimatedHardIronZVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of magnetometer bias.
     *
     * @return standard deviation of estimated z coordinate of magnetometer bias
     * or null if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronZStandardDeviationAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronZStandardDeviation(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of
     * magnetometer bias is available, false otherwise.
     */
    public boolean getEstimatedHardIronZStandardDeviationAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronZStandardDeviation());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated magnetometer bias coordinates.
     *
     * @return standard deviation of estimated magnetometer bias coordinates.
     */
    public MagneticFluxDensityTriad getEstimatedHardIronStandardDeviation() {
        return estimatedCovariance != null
                ? new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                getEstimatedHardIronXStandardDeviation(),
                getEstimatedHardIronYStandardDeviation(),
                getEstimatedHardIronZStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated magnetometer bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of magnetometer bias was available,
     * false otherwise.
     */
    public boolean getEstimatedHardIronStandardDeviation(final MagneticFluxDensityTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedHardIronXStandardDeviation(),
                    getEstimatedHardIronYStandardDeviation(),
                    getEstimatedHardIronZStandardDeviation(),
                    MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of magnetometer bias coordinates
     * expressed in Teslas (T).
     *
     * @return average of estimated standard deviation of magnetometer bias coordinates,
     * or null if not available.
     */
    public Double getEstimatedHardIronStandardDeviationAverage() {
        return estimatedCovariance != null
                ? (getEstimatedHardIronXStandardDeviation() + getEstimatedHardIronYStandardDeviation()
                + getEstimatedHardIronZStandardDeviation()) / 3.0
                : null;
    }

    /**
     * Gets average of estimated standard deviation of magnetometer bias coordinates.
     *
     * @return average of estimated standard deviation of magnetometer bias coordinates,
     * or null if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronStandardDeviationAverageAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronStandardDeviationAverage(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of magnetometer bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of magnetometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedHardIronStandardDeviationAverageAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronStandardDeviationAverage());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of magnetometer bias expressed in
     * Teslas (T).
     *
     * @return norm of estimated standard deviation of magnetometer bias or null
     * if not available.
     */
    public Double getEstimatedHardIronStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedHardIronXVariance() + getEstimatedHardIronYVariance()
                + getEstimatedHardIronZVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of magnetometer bias.
     *
     * @return norm of estimated standard deviation of magnetometer bias or null
     * if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronStandardDeviationNormAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronStandardDeviationNorm(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of magnetometer bias
     * is available, false otherwise.
     */
    public boolean getEstimatedHardIronStandardDeviationNormAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronStandardDeviationNorm());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #MINIMUM_MEASUREMENTS_COMMON_Z_AXIS}.
     *
     * @return size of subsets to be checked during robust estimation.
     */
    public int getPreliminarySubsetSize() {
        return preliminarySubsetSize;
    }

    /**
     * Sets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #MINIMUM_MEASUREMENTS_COMMON_Z_AXIS}.
     *
     * @param preliminarySubsetSize size of subsets to be checked during robust estimation.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is less than {@link #MINIMUM_MEASUREMENTS_COMMON_Z_AXIS}.
     */
    public void setPreliminarySubsetSize(final int preliminarySubsetSize) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (preliminarySubsetSize < MINIMUM_MEASUREMENTS_COMMON_Z_AXIS) {
            throw new IllegalArgumentException();
        }

        this.preliminarySubsetSize = preliminarySubsetSize;
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    public abstract RobustEstimatorMethod getMethod();

    /**
     * Creates a robust magnetometer calibrator.
     *
     * @param method robust estimator method.
     * @return a robust magnetometer calibrator.
     */
    public static RobustKnownMagneticFluxDensityNormMagnetometerCalibrator create(final RobustEstimatorMethod method) {

}

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where estimated gyroscope biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return column matrix containing x,y,z components of estimated gyroscope
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasX() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasY() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasZ() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedX() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[0], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedX(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedY() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[1], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedY(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedZ() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedZ(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @return estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeedTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated gyroscope bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AngularSpeedTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2],
                    AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration solution.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bgx, bgy, bgz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32,
     * gg13, gg23, gg33.
     * This is only available when result has been refined and covariance
     * is kept.
     *
     * @return estimated covariance matrix for estimated position.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets variance of estimated x coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated x coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasXVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasXStandardDeviation() {
        final var variance = getEstimatedBiasXVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasXStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasXStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasXStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasXStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated y coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasYVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasYStandardDeviation() {
        final var variance = getEstimatedBiasYVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasYStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasYStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasYStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasYStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated z coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasZVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasZStandardDeviation() {
        final var variance = getEstimatedBiasZVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasZStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasZStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasZStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasZStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @return standard deviation of estimated gyroscope bias coordinates.
     */
    public AngularSpeedTriad getEstimatedBiasStandardDeviation() {
        return estimatedCovariance != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                getEstimatedBiasXStandardDeviation(),
                getEstimatedBiasYStandardDeviation(),
                getEstimatedBiasZStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of gyroscope bias was available, false
     * otherwise.
     */
    public boolean getEstimatedBiasStandardDeviation(final AngularSpeedTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedBiasXStandardDeviation(),
                    getEstimatedBiasYStandardDeviation(),
                    getEstimatedBiasZStandardDeviation(),
                    AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates expressed
     * in radians per second (rad/s).
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null
     * if not available.
     */
    public Double getEstimatedBiasStandardDeviationAverage() {
        return estimatedCovariance != null
                ? (getEstimatedBiasXStandardDeviation() + getEstimatedBiasYStandardDeviation()
                + getEstimatedBiasZStandardDeviation()) / 3.0 : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationAverageAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationAverage(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationAverageAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationAverage());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias expressed in
     * radians per second (rad/s).
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    @Override
    public Double getEstimatedBiasStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedBiasXVariance() + getEstimatedBiasYVariance() + getEstimatedBiasZVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationNormAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationNorm(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias coordinates.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of gyroscope bias is
     * available, false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationNormAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationNorm());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #MINIMUM_MEASUREMENTS}.
     *
     * @return size of subsets to be checked during robust estimation.
     */
    public int getPreliminarySubsetSize() {
        return preliminarySubsetSize;
    }

    /**
     * Sets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #MINIMUM_MEASUREMENTS}.
     *
     * @param preliminarySubsetSize size of subsets to be checked during robust estimation.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is less than {@link #MINIMUM_MEASUREMENTS}.
     */
    public void setPreliminarySubsetSize(final int preliminarySubsetSize)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (preliminarySubsetSize < MINIMUM_MEASUREMENTS) {

this(sequences, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                accelerometerBias, accelerometerMa);
        this.listener = listener;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX,
            final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy,
            final double accelerometerSz, final double accelerometerMxy,
            final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx,
            final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                listener);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX, final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz,
            final double accelerometerMxy, final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx, final double accelerometerMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

}

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX,
            final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz,
            final double accelerometerMyx, final double accelerometerMyz,
            final double accelerometerMzx, final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy,
            final double accelerometerSz, final double accelerometerMxy,
            final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx,
            final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx,
                accelerometerMyz, accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

}

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasX() {
        return accelerometerBiasX;
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX known x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final double accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = accelerometerBiasX;
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasY() {
        return accelerometerBiasY;
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasY known y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final double accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = accelerometerBiasY;
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public double getAccelerometerBiasZ() {
        return accelerometerBiasZ;
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasZ known z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final double accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasXAsAcceleration() {
        return new Acceleration(accelerometerBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasX(final Acceleration accelerometerBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasYAsAcceleration() {
        return new Acceleration(accelerometerBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasY(final Acceleration accelerometerBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getAccelerometerBiasZAsAcceleration() {
        return new Acceleration(accelerometerBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getAccelerometerBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerometerBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z-coordinate of accelerometer bias to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBiasZ(final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final double accelerometerBiasX, final double accelerometerBiasY, final double accelerometerBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = accelerometerBiasX;
        this.accelerometerBiasY = accelerometerBiasY;
        this.accelerometerBiasZ = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerBiasX x-coordinate of accelerometer bias.
     * @param accelerometerBiasY y-coordinate of accelerometer bias.
     * @param accelerometerBiasZ z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerBias(
            final Acceleration accelerometerBiasX, final Acceleration accelerometerBiasY,
            final Acceleration accelerometerBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.accelerometerBiasX = convertAcceleration(accelerometerBiasX);
        this.accelerometerBiasY = convertAcceleration(accelerometerBiasY);
        this.accelerometerBiasZ = convertAcceleration(accelerometerBiasZ);
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public double[] getAccelerometerBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getAccelerometerBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getAccelerometerBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result[0] = accelerometerBiasX;
        result[1] = accelerometerBiasY;
        result[2] = accelerometerBiasZ;
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void setAccelerometerBias(final double[] accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (accelerometerBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias[0];
        accelerometerBiasY = accelerometerBias[1];
        accelerometerBiasZ = accelerometerBias[2];
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return known accelerometer bias.
     */
    @Override
    public Matrix getAccelerometerBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getAccelerometerBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getAccelerometerBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerBiasX);
        result.setElementAtIndex(1, accelerometerBiasY);
        result.setElementAtIndex(2, accelerometerBiasZ);
    }

    /**
     * Sets known accelerometer bias to be used to fix measured specific
     * force and find cross biases introduced by the accelerometer.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param accelerometerBias known accelerometer bias. Must be 3x1.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setAccelerometerBias(final Matrix accelerometerBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerBias.getRows() != BodyKinematics.COMPONENTS || accelerometerBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        accelerometerBiasX = accelerometerBias.getElementAtIndex(0);
        accelerometerBiasY = accelerometerBias.getElementAtIndex(1);
        accelerometerBiasZ = accelerometerBias.getElementAtIndex(2);
    }

    /**
     * Gets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer x scaling factor.
     */
    @Override
    public double getAccelerometerSx() {
        return accelerometerSx;
    }

    /**
     * Sets known accelerometer x scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSx(final double accelerometerSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
    }

    /**
     * Gets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer y scaling factor.
     */
    @Override
    public double getAccelerometerSy() {
        return accelerometerSy;
    }

    /**
     * Sets known accelerometer y scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSy known accelerometer y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSy(final double accelerometerSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSy = accelerometerSy;
    }

    /**
     * Gets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @return known accelerometer z scaling factor.
     */
    @Override
    public double getAccelerometerSz() {
        return accelerometerSz;
    }

    /**
     * Sets known accelerometer z scaling factor to be used to fix measured
     * specific force and find cross biases introduced by the accelerometer.
     *
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerSz(final double accelerometerSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Gets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-y cross coupling error.
     */
    @Override
    public double getAccelerometerMxy() {
        return accelerometerMxy;
    }

    /**
     * Sets known accelerometer x-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxy(final double accelerometerMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
    }

    /**
     * Gets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer x-z cross coupling error.
     */
    @Override
    public double getAccelerometerMxz() {
        return accelerometerMxz;
    }

    /**
     * Sets known accelerometer x-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxz known accelerometer x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMxz(final double accelerometerMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxz = accelerometerMxz;
    }

    /**
     * Gets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-x cross coupling error.
     */
    @Override
    public double getAccelerometerMyx() {
        return accelerometerMyx;
    }

    /**
     * Sets known accelerometer y-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyx(final double accelerometerMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyx = accelerometerMyx;
    }

    /**
     * Gets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer y-z cross coupling error.
     */
    @Override
    public double getAccelerometerMyz() {
        return accelerometerMyz;
    }

    /**
     * Sets known accelerometer y-z cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMyz(final double accelerometerMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMyz = accelerometerMyz;
    }

    /**
     * Gets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-x cross coupling error.
     */
    @Override
    public double getAccelerometerMzx() {
        return accelerometerMzx;
    }

    /**
     * Sets known accelerometer z-x cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzx(final double accelerometerMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzx = accelerometerMzx;
    }

    /**
     * Gets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @return known accelerometer z-y cross coupling error.
     */
    @Override
    public double getAccelerometerMzy() {
        return accelerometerMzy;
    }

    /**
     * Sets known accelerometer z-y cross coupling error to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerMzy(final double accelerometerMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors to be used to fix measured
     * specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerSx known accelerometer x scaling factor.
     * @param accelerometerSy known accelerometer y scaling factor.
     * @param accelerometerSz known accelerometer z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerSx = accelerometerSx;
        this.accelerometerSy = accelerometerSy;
        this.accelerometerSz = accelerometerSz;
    }

    /**
     * Sets known accelerometer cross coupling errors to be used to fix
     * measured specific force and find cross biases introduced by the
     * accelerometer.
     *
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerCrossCouplingErrors(
            final double accelerometerMxy, final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx, final double accelerometerMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.accelerometerMxy = accelerometerMxy;
        this.accelerometerMxz = accelerometerMxz;
        this.accelerometerMyx = accelerometerMyx;
        this.accelerometerMyz = accelerometerMyz;
        this.accelerometerMzx = accelerometerMzx;
        this.accelerometerMzy = accelerometerMzy;
    }

    /**
     * Sets known accelerometer scaling factors and cross coupling errors
     * to be used to fix measured specific force and find cross biases
     * introduced by the accelerometer.
     *
     * @param accelerometerSx  known accelerometer x scaling factor.
     * @param accelerometerSy  known accelerometer y scaling factor.
     * @param accelerometerSz  known accelerometer z scaling factor.
     * @param accelerometerMxy known accelerometer x-y cross coupling
     *                         error.
     * @param accelerometerMxz known accelerometer x-z cross coupling
     *                         error.
     * @param accelerometerMyx known accelerometer y-x cross coupling
     *                         error.
     * @param accelerometerMyz known accelerometer y-z cross coupling
     *                         error.
     * @param accelerometerMzx known accelerometer z-x cross coupling
     *                         error.
     * @param accelerometerMzy known accelerometer z-y cross coupling
     *                         error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setAccelerometerScalingFactorsAndCrossCouplingErrors(
            final double accelerometerSx, final double accelerometerSy, final double accelerometerSz,
            final double accelerometerMxy, final double accelerometerMxz, final double accelerometerMyx,
            final double accelerometerMyz, final double accelerometerMzx, final double accelerometerMzy)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setAccelerometerScalingFactors(accelerometerSx, accelerometerSy, accelerometerSz);
        setAccelerometerCrossCouplingErrors(accelerometerMxy, accelerometerMxz, accelerometerMyx, accelerometerMyz,
                accelerometerMzx, accelerometerMzy);
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @return known accelerometer scale factors and cross coupling
     * errors matrix.
     */
    @Override
    public Matrix getAccelerometerMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getAccelerometerMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getAccelerometerMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, accelerometerSx);
        result.setElementAtIndex(1, accelerometerMyx);
        result.setElementAtIndex(2, accelerometerMzx);

        result.setElementAtIndex(3, accelerometerMxy);
        result.setElementAtIndex(4, accelerometerSy);
        result.setElementAtIndex(5, accelerometerMzy);

        result.setElementAtIndex(6, accelerometerMxz);
        result.setElementAtIndex(7, accelerometerMyz);
        result.setElementAtIndex(8, accelerometerSz);
    }

    /**
     * Sets known accelerometer scale factors and cross coupling
     * errors matrix.
     *
     * @param accelerometerMa known accelerometer scale factors and
     *                        cross coupling errors matrix. Must be 3x3.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setAccelerometerMa(final Matrix accelerometerMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (accelerometerMa.getRows() != BodyKinematics.COMPONENTS
                || accelerometerMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        accelerometerSx = accelerometerMa.getElementAtIndex(0);
        accelerometerMyx = accelerometerMa.getElementAtIndex(1);
        accelerometerMzx = accelerometerMa.getElementAtIndex(2);

        accelerometerMxy = accelerometerMa.getElementAtIndex(3);
        accelerometerSy = accelerometerMa.getElementAtIndex(4);
        accelerometerMzy = accelerometerMa.getElementAtIndex(5);

        accelerometerMxz = accelerometerMa.getElementAtIndex(6);
        accelerometerMyz = accelerometerMa.getElementAtIndex(7);
        accelerometerSz = accelerometerMa.getElementAtIndex(8);
    }

} catch (final FittingException | AlgebraException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where estimated gyroscope biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return column matrix containing x,y,z components of estimated gyroscope
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasX() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasY() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasZ() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedX() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[0], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedX(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedY() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[1], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedY(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedZ() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedZ(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @return estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeedTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated gyroscope bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AngularSpeedTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bgx, bgy, bgz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32,
     * gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets variance of estimated x coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated x coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasXVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasXStandardDeviation() {
        final var variance = getEstimatedBiasXVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasXStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasXStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasXStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasXStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated y coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasYVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasYStandardDeviation() {
        final var variance = getEstimatedBiasYVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasYStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasYStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasYStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasYStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated z coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasZVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasZStandardDeviation() {
        final var variance = getEstimatedBiasZVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasZStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasZStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasZStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasZStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @return standard deviation of estimated gyroscope bias coordinates.
     */
    public AngularSpeedTriad getEstimatedBiasStandardDeviation() {
        return estimatedCovariance != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                getEstimatedBiasXStandardDeviation(),
                getEstimatedBiasYStandardDeviation(),
                getEstimatedBiasZStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of gyroscope bias was available, false
     * otherwise.
     */
    public boolean getEstimatedBiasStandardDeviation(final AngularSpeedTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedBiasXStandardDeviation(),
                    getEstimatedBiasYStandardDeviation(),
                    getEstimatedBiasZStandardDeviation(),
                    AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates expressed
     * in radians per second (rad/s).
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null
     * if not available.
     */
    public Double getEstimatedBiasStandardDeviationAverage() {
        return estimatedCovariance != null
                ? (getEstimatedBiasXStandardDeviation() + getEstimatedBiasYStandardDeviation()
                + getEstimatedBiasZStandardDeviation()) / 3.0 : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationAverageAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationAverage(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationAverageAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationAverage());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias expressed in
     * radians per second (rad/s).
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    @Override
    public Double getEstimatedBiasStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedBiasXVariance() + getEstimatedBiasYVariance() + getEstimatedBiasZVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationNormAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationNorm(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias coordinates.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of gyroscope bias is
     * available, false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationNormAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationNorm());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed
     * for both the accelerometer and gyroscope and when G-dependent cross
     * biases are being estimated.
     *
     * @throws AlgebraException                         if accelerometer parameters prevent fixing
     *                                                  measured accelerometer values due to numerical instabilities.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateCommonAxisAndGDependentCrossBiases() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {

} catch (final FittingException | AlgebraException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where estimated gyroscope biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return column matrix containing x,y,z components of estimated gyroscope
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasX() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasY() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasZ() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedX() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[0], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedX(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedY() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[1], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedY(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedZ() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedZ(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @return estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeedTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated gyroscope bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AngularSpeedTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bgx, bgy, bgz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32,
     * gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets variance of estimated x coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated x coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasXVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasXStandardDeviation() {
        final var variance = getEstimatedBiasXVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasXStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasXStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasXStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasXStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated y coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasYVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasYStandardDeviation() {
        final var variance = getEstimatedBiasYVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasYStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasYStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasYStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasYStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated z coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasZVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasZStandardDeviation() {
        final var variance = getEstimatedBiasZVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasZStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasZStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasZStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasZStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @return standard deviation of estimated gyroscope bias coordinates.
     */
    public AngularSpeedTriad getEstimatedBiasStandardDeviation() {
        return estimatedCovariance != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                getEstimatedBiasXStandardDeviation(),
                getEstimatedBiasYStandardDeviation(),
                getEstimatedBiasZStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of gyroscope bias was available, false
     * otherwise.
     */
    public boolean getEstimatedBiasStandardDeviation(final AngularSpeedTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedBiasXStandardDeviation(),
                    getEstimatedBiasYStandardDeviation(),
                    getEstimatedBiasZStandardDeviation(),
                    AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates expressed
     * in radians per second (rad/s).
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null
     * if not available.
     */
    public Double getEstimatedBiasStandardDeviationAverage() {
        return estimatedCovariance != null
                ? (getEstimatedBiasXStandardDeviation() + getEstimatedBiasYStandardDeviation()
                + getEstimatedBiasZStandardDeviation()) / 3.0 : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationAverageAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationAverage(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationAverageAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationAverage());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias expressed in
     * radians per second (rad/s).
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    @Override
    public Double getEstimatedBiasStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedBiasXVariance() + getEstimatedBiasYVariance() + getEstimatedBiasZVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationNormAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationNorm(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias coordinates.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of gyroscope bias is
     * available, false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationNormAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationNorm());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed
     * for both the accelerometer and gyroscope and when G-dependent cross
     * biases are being estimated.
     *
     * @throws AlgebraException                         if accelerometer parameters prevent fixing
     *                                                  measured accelerometer values due to numerical instabilities.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateCommonAxisAndGDependentCrossBiases() throws AlgebraException, FittingException,

listener.onCalibrateEnd((C) this);
            }

        } catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return array containing x,y,z components of estimated accelerometer biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where estimated accelerometer biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return column matrix containing x,y,z components of estimated accelerometer
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFx() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return y coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFy() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return z coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFz() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated accelerometer bias.
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Acceleration getEstimatedBiasFxAsAcceleration() {
        return estimatedBiases != null ?
                new Acceleration(estimatedBiases[0], AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasFxAsAcceleration(final Acceleration result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated accelerometer bias.
     *
     * @return y coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Acceleration getEstimatedBiasFyAsAcceleration() {
        return estimatedBiases != null ?
                new Acceleration(estimatedBiases[1], AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasFyAsAcceleration(final Acceleration result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated accelerometer bias.
     *
     * @return z coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Acceleration getEstimatedBiasFzAsAcceleration() {
        return estimatedBiases != null ?
                new Acceleration(estimatedBiases[2], AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasFzAsAcceleration(final Acceleration result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated accelerometer bias.
     *
     * @return estimated accelerometer bias or null if not available.
     */
    @Override
    public AccelerationTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null ?
                new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND,
                        estimatedBiases[0], estimatedBiases[1], estimatedBiases[2]) : null;
    }

    /**
     * Gets estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated accelerometer bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AccelerationTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(estimatedBiases[0], estimatedBiases[1], estimatedBiases[2],
                    AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }


    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {
        return estimatedMa;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bx, by, bz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy.
     *
     * @return estimated covariance matrix for estimated calibration parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets variance of estimated x coordinate of accelerometer bias expressed in (m^2/s^4).
     *
     * @return variance of estimated x coordinate of accelerometer bias or null if not available.
     */
    public Double getEstimatedBiasFxVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of accelerometer bias expressed in
     * meters per squared second (m/s^2).
     *
     * @return standard deviation of estimated x coordinate of accelerometer bias or null if not
     * available.
     */
    public Double getEstimatedBiasFxStandardDeviation() {
        final var variance = getEstimatedBiasFxVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of accelerometer bias.
     *
     * @return standard deviation of estimated x coordinate of accelerometer bias or null if not
     * available.
     */
    public Acceleration getEstimatedBiasFxStandardDeviationAsAcceleration() {
        return estimatedCovariance != null
                ? new Acceleration(getEstimatedBiasFxStandardDeviation(), AccelerationUnit.METERS_PER_SQUARED_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of accelerometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasFxStandardDeviationAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasFxStandardDeviation());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of accelerometer bias expressed in (m^2/s^4).
     *
     * @return variance of estimated y coordinate of accelerometer bias or null if not available.
     */
    public Double getEstimatedBiasFyVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of accelerometer bias expressed in
     * meters per squared second (m/s^2).
     *
     * @return standard deviation of estimated y coordinate of accelerometer bias or null if not
     * available.
     */
    public Double getEstimatedBiasFyStandardDeviation() {
        final var variance = getEstimatedBiasFyVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of accelerometer bias.
     *
     * @return standard deviation of estimated y coordinate of accelerometer bias or null if not
     * available.
     */
    public Acceleration getEstimatedBiasFyStandardDeviationAsAcceleration() {
        return estimatedCovariance != null
                ? new Acceleration(getEstimatedBiasFyStandardDeviation(), AccelerationUnit.METERS_PER_SQUARED_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of accelerometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasFyStandardDeviationAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasFyStandardDeviation());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of accelerometer bias expressed in (m^2/s^4).
     *
     * @return variance of estimated z coordinate of accelerometer bias or null if not available.
     */
    public Double getEstimatedBiasFzVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of accelerometer bias expressed in
     * meters per squared second (m/s^2).
     *
     * @return standard deviation of estimated z coordinate of accelerometer bias or null if not
     * available.
     */
    public Double getEstimatedBiasFzStandardDeviation() {
        final var variance = getEstimatedBiasFzVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of accelerometer bias.
     *
     * @return standard deviation of estimated z coordinate of accelerometer bias or null if not
     * available.
     */
    public Acceleration getEstimatedBiasFzStandardDeviationAsAcceleration() {
        return estimatedCovariance != null
                ? new Acceleration(getEstimatedBiasFzStandardDeviation(), AccelerationUnit.METERS_PER_SQUARED_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of accelerometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasFzStandardDeviationAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasFzStandardDeviation());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated accelerometer bias coordinates.
     *
     * @return standard deviation of estimated accelerometer bias coordinates.
     */
    public AccelerationTriad getEstimatedBiasStandardDeviation() {
        return estimatedCovariance != null ?
                new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND,
                        getEstimatedBiasFxStandardDeviation(),
                        getEstimatedBiasFyStandardDeviation(),
                        getEstimatedBiasFzStandardDeviation()) : null;
    }

    /**
     * Gets standard deviation of estimated accelerometer bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of accelerometer bias was available, false
     * otherwise.
     */
    public boolean getEstimatedBiasStandardDeviation(final AccelerationTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedBiasFxStandardDeviation(),
                    getEstimatedBiasFyStandardDeviation(),
                    getEstimatedBiasFzStandardDeviation(),
                    AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of accelerometer bias coordinates expressed
     * in meters per squared second (m/s^2).
     *
     * @return average of estimated standard deviation of accelerometer bias coordinates or null
     * if not available.
     */
    public Double getEstimatedBiasStandardDeviationAverage() {
        return estimatedCovariance != null ?
                (getEstimatedBiasFxStandardDeviation() + getEstimatedBiasFyStandardDeviation()
                        + getEstimatedBiasFzStandardDeviation()) / 3.0 : null;
    }

    /**
     * Gets average of estimated standard deviation of accelerometer bias coordinates.
     *
     * @return average of estimated standard deviation of accelerometer bias coordinates or null.
     */
    public Acceleration getEstimatedBiasStandardDeviationAverageAsAcceleration() {
        return estimatedCovariance != null ?
                new Acceleration(getEstimatedBiasStandardDeviationAverage(),
                        AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets average of estimated standard deviation of accelerometer bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of accelerometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationAverageAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationAverage());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of accelerometer bias expressed in
     * meters per squared second (m/s^2).
     * This can be used as the initial accelerometer bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of accelerometer bias or null
     * if not available.
     */
    @Override
    public Double getEstimatedBiasStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedBiasFxVariance() + getEstimatedBiasFyVariance() + getEstimatedBiasFzVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of accelerometer bias.
     * This can be used as the initial accelerometer bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of accelerometer bias or null
     * if not available.
     */
    public Acceleration getEstimatedBiasStandardDeviationNormAsAcceleration() {
        return estimatedCovariance != null
                ? new Acceleration(getEstimatedBiasStandardDeviationNorm(), AccelerationUnit.METERS_PER_SQUARED_SECOND)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of accelerometer bias coordinates.
     * This can be used as the initial accelerometer bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of accelerometer bias is
     * available, false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationNormAsAcceleration(final Acceleration result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationNorm());
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

} catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where estimated gyroscope biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return column matrix containing x,y,z components of estimated gyroscope
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasX() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasY() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasZ() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedX() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[0], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedX(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedY() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[1], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedY(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedZ() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedZ(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @return estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeedTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated gyroscope bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AngularSpeedTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2],
                    AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null
                ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bgx, bgy, bgz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32,
     * gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets variance of estimated x coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated x coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasXVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasXStandardDeviation() {
        final var variance = getEstimatedBiasXVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasXStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasXStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasXStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasXStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated y coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasYVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasYStandardDeviation() {
        final var variance = getEstimatedBiasYVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasYStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasYStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasYStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasYStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated z coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasZVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasZStandardDeviation() {
        final var variance = getEstimatedBiasZVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasZStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasZStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasZStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasZStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @return standard deviation of estimated gyroscope bias coordinates.
     */
    public AngularSpeedTriad getEstimatedBiasStandardDeviation() {
        return estimatedCovariance != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                getEstimatedBiasXStandardDeviation(),
                getEstimatedBiasYStandardDeviation(),
                getEstimatedBiasZStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of gyroscope bias was available, false
     * otherwise.
     */
    public boolean getEstimatedBiasStandardDeviation(final AngularSpeedTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedBiasXStandardDeviation(),
                    getEstimatedBiasYStandardDeviation(),
                    getEstimatedBiasZStandardDeviation(),
                    AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates expressed
     * in radians per second (rad/s).
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null
     * if not available.
     */
    public Double getEstimatedBiasStandardDeviationAverage() {
        return estimatedCovariance != null
                ? (getEstimatedBiasXStandardDeviation() + getEstimatedBiasYStandardDeviation()
                + getEstimatedBiasZStandardDeviation()) / 3.0
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationAverageAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationAverage(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationAverageAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationAverage());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias expressed in
     * radians per second (rad/s).
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    @Override
    public Double getEstimatedBiasStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedBiasXVariance() + getEstimatedBiasYVariance() + getEstimatedBiasZVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationNormAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationNorm(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias coordinates.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of gyroscope bias is
     * available, false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationNormAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationNorm());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed for both
     * the accelerometer and gyroscope.
     *
     * @throws AlgebraException                         if there are numerical errors.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateCommonAxis() throws AlgebraException, FittingException,

} catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @return array containing x,y,z components of estimated magnetometer
     * hard-iron biases.
     */
    @Override
    public double[] getEstimatedHardIron() {
        return estimatedHardIron;
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where estimated magnetometer biases will be
     *               stored.
     * @return true if result instance was updated, false otherwise (when
     * estimation is not yet available).
     */
    @Override
    public boolean getEstimatedHardIron(final double[] result) {
        if (estimatedHardIron != null) {
            System.arraycopy(estimatedHardIron, 0, result, 0, estimatedHardIron.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @return column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases.
     */
    @Override
    public Matrix getEstimatedHardIronAsMatrix() {
        return estimatedHardIron != null ? Matrix.newFromArray(estimatedHardIron) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedHardIronAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedHardIron != null) {
            result.fromArray(estimatedHardIron);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return x coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronX() {
        return estimatedHardIron != null ? estimatedHardIron[0] : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return y coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronY() {
        return estimatedHardIron != null ? estimatedHardIron[1] : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return z coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronZ() {
        return estimatedHardIron != null ? estimatedHardIron[2] : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @return x coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronXAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[0], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[0]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @return y coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronYAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[1], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[1]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @return z coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronZAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[2], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[2]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @return estimated magnetometer bias or null if not available.
     */
    @Override
    public MagneticFluxDensityTriad getEstimatedHardIronAsTriad() {
        return estimatedHardIron != null
                ? new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2])
                : null;
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronAsTriad(final MagneticFluxDensityTriad result) {
        if (estimatedHardIron != null) {
            result.setValueCoordinatesAndUnit(estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2],
                    MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bx, by, bz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy.
     *
     * @return estimated covariance matrix for estimated calibration parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets variance of estimated x coordinate of magnetometer bias expressed in
     * squared Teslas (T^2).
     *
     * @return variance of estimated x coordinate of magnetometer bias or null if
     * not available.
     */
    public Double getEstimatedHardIronXVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of magnetometer bias
     * expressed in Teslas (T).
     *
     * @return standard deviation of estimated x coordinate of magnetometer bias
     * or null if not available.
     */
    public Double getEstimatedHardIronXStandardDeviation() {
        final var variance = getEstimatedHardIronXVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of magnetometer bias.
     *
     * @return standard deviation of estimated x coordinate of magnetometer bias
     * or null if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronXStandardDeviationAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronXStandardDeviation(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of
     * magnetometer bias is available, false otherwise.
     */
    public boolean getEstimatedHardIronXStandardDeviationAsMagneticFluxDensity(
            final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronXStandardDeviation());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of magnetometer bias expressed in
     * squared Teslas (T^2).
     *
     * @return variance of estimated y coordinate of magnetometer bias or null if
     * not available.
     */
    public Double getEstimatedHardIronYVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of magnetometer bias
     * expressed in Teslas (T).
     *
     * @return standard deviation of estimated y coordinate of magnetometer bias
     * or null if not available.
     */
    public Double getEstimatedHardIronYStandardDeviation() {
        final var variance = getEstimatedHardIronYVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of magnetometer bias.
     *
     * @return standard deviation of estimated y coordinate of magnetometer bias
     * or null if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronYStandardDeviationAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronYStandardDeviation(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of
     * magnetometer bias is available, false otherwise.
     */
    public boolean getEstimatedHardIronYStandardDeviationAsMagneticFluxDensity(
            final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronYStandardDeviation());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of magnetometer bias expressed in
     * squared Teslas (T^2).
     *
     * @return variance of estimated z coordinate of magnetometer bias or null if
     * not available.
     */
    public Double getEstimatedHardIronZVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of magnetometer bias
     * expressed in Teslas (T).
     *
     * @return standard deviation of estimated z coordinate of magnetometer bias
     * or null if not available.
     */
    public Double getEstimatedHardIronZStandardDeviation() {
        final var variance = getEstimatedHardIronZVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of magnetometer bias.
     *
     * @return standard deviation of estimated z coordinate of magnetometer bias
     * or null if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronZStandardDeviationAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronZStandardDeviation(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of
     * magnetometer bias is available, false otherwise.
     */
    public boolean getEstimatedHardIronZStandardDeviationAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronZStandardDeviation());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated magnetometer bias coordinates.
     *
     * @return standard deviation of estimated magnetometer bias coordinates.
     */
    public MagneticFluxDensityTriad getEstimatedHardIronStandardDeviation() {
        return estimatedCovariance != null
                ? new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                getEstimatedHardIronXStandardDeviation(),
                getEstimatedHardIronYStandardDeviation(),
                getEstimatedHardIronZStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated magnetometer bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of magnetometer bias was available,
     * false otherwise.
     */
    public boolean getEstimatedHardIronStandardDeviation(final MagneticFluxDensityTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedHardIronXStandardDeviation(),
                    getEstimatedHardIronYStandardDeviation(),
                    getEstimatedHardIronZStandardDeviation(),
                    MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of magnetometer bias coordinates
     * expressed in Teslas (T).
     *
     * @return average of estimated standard deviation of magnetometer bias coordinates,
     * or null if not available.
     */
    public Double getEstimatedHardIronStandardDeviationAverage() {
        return estimatedCovariance != null
                ? (getEstimatedHardIronXStandardDeviation() + getEstimatedHardIronYStandardDeviation()
                + getEstimatedHardIronZStandardDeviation()) / 3.0
                : null;
    }

    /**
     * Gets average of estimated standard deviation of magnetometer bias coordinates.
     *
     * @return average of estimated standard deviation of magnetometer bias coordinates,
     * or null if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronStandardDeviationAverageAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronStandardDeviationAverage(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of magnetometer bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of magnetometer bias is available,
     * false otherwise.
     */
    public boolean getEstimatedHardIronStandardDeviationAverageAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronStandardDeviationAverage());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of magnetometer bias expressed in
     * Teslas (T).
     *
     * @return norm of estimated standard deviation of magnetometer bias or null
     * if not available.
     */
    public Double getEstimatedHardIronStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedHardIronXVariance() + getEstimatedHardIronYVariance()
                + getEstimatedHardIronZVariance()) : null;
    }

    /**
     * Gets norm of estimated standard deviation of magnetometer bias.
     *
     * @return norm of estimated standard deviation of magnetometer bias or null
     * if not available.
     */
    public MagneticFluxDensity getEstimatedHardIronStandardDeviationNormAsMagneticFluxDensity() {
        return estimatedCovariance != null
                ? new MagneticFluxDensity(getEstimatedHardIronStandardDeviationNorm(), MagneticFluxDensityUnit.TESLA)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of magnetometer bias
     * is available, false otherwise.
     */
    public boolean getEstimatedHardIronStandardDeviationNormAsMagneticFluxDensity(
            final MagneticFluxDensity result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedHardIronStandardDeviationNorm());
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

public void getEcefVelocity(final ECEFVelocity result) {
        result.setCoordinates(vx, vy, vz);
    }

    /**
     * Gets estimated ECEF user velocity.
     *
     * @return estimated ECEF user velocity.
     */
    public ECEFVelocity getEcefVelocity() {
        return new ECEFVelocity(vx, vy, vz);
    }

    /**
     * Sets estimated ECEF user velocity.
     *
     * @param ecefVelocity estimated ECEF user velocity.
     */
    public void setEcefVelocity(final ECEFVelocity ecefVelocity) {
        vx = ecefVelocity.getVx();
        vy = ecefVelocity.getVy();
        vz = ecefVelocity.getVz();
    }

    /**
     * Gets x coordinate of estimated ECEF user position.
     *
     * @param result instance where x coordinate of estimated ECEF user position
     *               will be stored.
     */
    public void getDistanceX(final Distance result) {
        result.setValue(x);
        result.setUnit(DistanceUnit.METER);
    }

    /**
     * Gets x coordinate of estimated ECEF user position.
     *
     * @return x coordinate of estimated ECEF user position.
     */
    public Distance getDistanceX() {
        return new Distance(x, DistanceUnit.METER);
    }

    /**
     * Sets x coordinate of estimated ECEF user position.
     *
     * @param x x coordinate of estimated ECEF user position.
     */
    public void setDistanceX(final Distance x) {
        this.x = DistanceConverter.convert(x.getValue().doubleValue(), x.getUnit(), DistanceUnit.METER);
    }

    /**
     * Gets y coordinate of estimated ECEF user position.
     *
     * @param result instance where y coordinate of estimated ECEF user position
     *               will be stored.
     */
    public void getDistanceY(final Distance result) {
        result.setValue(y);
        result.setUnit(DistanceUnit.METER);
    }

    /**
     * Gets y coordinate of estimated ECEF user position.
     *
     * @return y coordinate of estimated ECEF user position.
     */
    public Distance getDistanceY() {
        return new Distance(y, DistanceUnit.METER);
    }

    /**
     * Sets y coordinate of estimated ECEF user position.
     *
     * @param y y coordinate of estimated ECEF user position.
     */
    public void setDistanceY(final Distance y) {
        this.y = DistanceConverter.convert(y.getValue().doubleValue(), y.getUnit(), DistanceUnit.METER);
    }

    /**
     * Gets z coordinate of estimated ECEF user position.
     *
     * @param result instance where z coordinate of estimated ECEF user position
     *               will be stored.
     */
    public void getDistanceZ(final Distance result) {
        result.setValue(z);
        result.setUnit(DistanceUnit.METER);
    }

    /**
     * Gets z coordinate of estimated ECEF user position.
     *
     * @return z coordinate of estimated ECEF user position.
     */
    public Distance getDistanceZ() {
        return new Distance(z, DistanceUnit.METER);
    }

    /**
     * Sets z coordinate of estimated ECEF user position.
     *
     * @param z z coordinate of estimated ECEF user position.
     */
    public void setDistanceZ(final Distance z) {
        this.z = DistanceConverter.convert(z.getValue().doubleValue(), z.getUnit(), DistanceUnit.METER);
    }

    /**
     * Sets coordinates of estimated ECEF user position.
     *
     * @param x x coordinate of estimated ECEF user position.
     * @param y y coordinate of estimated ECEF user position.
     * @param z z coordinate of estimated ECEF user position.
     */
    public void setPositionCoordinates(final Distance x, final Distance y, final Distance z) {
        setDistanceX(x);
        setDistanceY(y);
        setDistanceZ(z);
    }

    /**
     * Gets estimated ECEF user position expressed in meters (m).
     *
     * @param result instance where estimated ECEF user position expressed
     *               in meters (m) will be stored.
     */
    public void getPosition(final Point3D result) {
        result.setInhomogeneousCoordinates(x, y, z);
    }

    /**
     * Gets estimated ECEF user position expressed in meters (m).
     *
     * @return estimated ECEF user position expressed in meters (m).
     */
    public Point3D getPosition() {
        return new InhomogeneousPoint3D(x, y, z);
    }

    /**
     * Sets estimated ECEF user position expressed in meters (m).
     *
     * @param position estimated ECEF user position expressed in
     *                 meters (m).
     */
    public void setPosition(final Point3D position) {
        x = position.getInhomX();
        y = position.getInhomY();
        z = position.getInhomZ();
    }

    /**
     * Gets estimated ECEF user position.
     *
     * @param result instance where estimated ECEF user position
     *               will be stored.
     */
    public void getEcefPosition(final ECEFPosition result) {
        result.setCoordinates(x, y, z);
    }

    /**
     * Gets estimated ECEF user position.
     *
     * @return estimated ECEF user position.
     */
    public ECEFPosition getEcefPosition() {
        return new ECEFPosition(x, y, z);
    }

    /**
     * Sets estimated ECEF user position.
     *
     * @param ecefPosition estimated ECEF user position.
     */
    public void setEcefPosition(final ECEFPosition ecefPosition) {
        x = ecefPosition.getX();
        y = ecefPosition.getY();
        z = ecefPosition.getZ();
    }

    /**
     * Gets estimated ECEF user position and velocity.
     *
     * @param result instance where estimated ECEF user position and velocity
     *               will be stored.
     */
    public void getPositionAndVelocity(final ECEFPositionAndVelocity result) {
        result.setPositionCoordinates(x, y, z);
        result.setVelocityCoordinates(vx, vy, vz);
    }

    /**
     * Gets estimated ECEF user position and velocity.
     *
     * @return estimated ECEF user position and velocity.
     */
    public ECEFPositionAndVelocity getPositionAndVelocity() {
        return new ECEFPositionAndVelocity(x, y, z, vx, vy, vz);
    }

    /**
     * Sets estimated ECEF user position and velocity.
     *
     * @param positionAndVelocity estimated ECEF user position and velocity.
     */
    public void setPositionAndVelocity(final ECEFPositionAndVelocity positionAndVelocity) {
        x = positionAndVelocity.getX();
        y = positionAndVelocity.getY();
        z = positionAndVelocity.getZ();
        vx = positionAndVelocity.getVx();
        vy = positionAndVelocity.getVy();
        vz = positionAndVelocity.getVz();
    }

    /**
     * Gets body to ECEF frame containing coordinate transformation, position and
     * velocity.
     *
     * @param result instance where body to ECEF frame will be stored.
     * @return true if result was updated, false otherwise.
     */
    public boolean getFrame(final ECEFFrame result) {
        if (bodyToEcefCoordinateTransformationMatrix != null) {
            try {
                result.setCoordinateTransformation(getC());
            } catch (final InvalidSourceAndDestinationFrameTypeException | InvalidRotationMatrixException e) {
                return false;
            }
            result.setCoordinates(x, y, z);
            result.setVelocityCoordinates(vx, vy, vz);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets body to ECEF frame containing coordinate transformation, position and
     * velocity.
     *
     * @return body to ECEF frame.
     */
    public ECEFFrame getFrame() {
        if (bodyToEcefCoordinateTransformationMatrix != null) {
            try {
                return new ECEFFrame(x, y, z, vx, vy, vz, getC());
            } catch (final InvalidSourceAndDestinationFrameTypeException | InvalidRotationMatrixException e) {
                return null;
            }
        } else {
            return null;
        }
    }

    /**
     * Sets body to ECEF frame containing coordinate transformation, position and
     * velocity.
     *
     * @param frame body to ECEF frame to be set.
     */
    public void setFrame(final ECEFFrame frame) {
        x = frame.getX();
        y = frame.getY();
        z = frame.getZ();

        vx = frame.getVx();
        vy = frame.getVy();
        vz = frame.getVz();

        if (bodyToEcefCoordinateTransformationMatrix != null) {
            frame.getCoordinateTransformationMatrix(bodyToEcefCoordinateTransformationMatrix);
        } else {
            bodyToEcefCoordinateTransformationMatrix = frame.getCoordinateTransformationMatrix();
        }
    }

    /**
     * Gets estimated accelerometer bias resolved around x axis.
     *
     * @param result instance where estimated accelerometer bias resolved around
     *               x axis will be stored.
     */
    public void getAccelerationBiasXAsAcceleration(final Acceleration result) {
        result.setValue(accelerationBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets estimated accelerometer bias resolved around x axis.
     *
     * @return estimated accelerometer bias resolved around x axis.
     */
    public Acceleration getAccelerationBiasXAsAcceleration() {
        return new Acceleration(accelerationBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets estimated accelerometer bias resolved around x axis.
     *
     * @param accelerationBiasX estimated accelerometer bias resolved
     *                          around x axis.
     */
    public void setAccelerationBiasX(final Acceleration accelerationBiasX) {
        this.accelerationBiasX = AccelerationConverter.convert(accelerationBiasX.getValue().doubleValue(),
                accelerationBiasX.getUnit(), AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets estimated accelerometer bias resolved around y axis.
     *
     * @param result instance where estimated accelerometer bias resolved around
     *               y axis will be stored.
     */
    public void getAccelerationBiasYAsAcceleration(final Acceleration result) {
        result.setValue(accelerationBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets estimated accelerometer bias resolved around y axis.
     *
     * @return estimated accelerometer bias resolved around y axis.
     */
    public Acceleration getAccelerationBiasYAsAcceleration() {
        return new Acceleration(accelerationBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets estimated accelerometer bias resolved around y axis.
     *
     * @param accelerationBiasY estimated accelerometer bias resolved
     *                          around y axis.
     */
    public void setAccelerationBiasY(final Acceleration accelerationBiasY) {
        this.accelerationBiasY = AccelerationConverter.convert(accelerationBiasY.getValue().doubleValue(),
                accelerationBiasY.getUnit(), AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets estimated accelerometer bias resolved around z axis.
     *
     * @param result instance where estimated accelerometer bias resolved around
     *               z axis will be stored.
     */
    public void getAccelerationBiasZAsAcceleration(final Acceleration result) {
        result.setValue(accelerationBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets estimated accelerometer bias resolved around z axis.
     *
     * @return estimated accelerometer bias resolved around z axis.
     */
    public Acceleration getAccelerationBiasZAsAcceleration() {
        return new Acceleration(accelerationBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets estimated accelerometer bias resolved around z axis.
     *
     * @param accelerationBiasZ estimated accelerometer bias resolved
     *                          around z axis.
     */
    public void setAccelerationBiasZ(final Acceleration accelerationBiasZ) {
        this.accelerationBiasZ = AccelerationConverter.convert(accelerationBiasZ.getValue().doubleValue(),
                accelerationBiasZ.getUnit(), AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets estimated accelerometer bias coordinates.
     *
     * @param accelerationBiasX estimated accelerometer bias resolved around x axis.
     * @param accelerationBiasY estimated accelerometer bias resolved around y axis.
     * @param accelerationBiasZ estimated accelerometer bias resolved around z axis.
     */
    public void setAccelerationBiasCoordinates(
            final Acceleration accelerationBiasX, final Acceleration accelerationBiasY,
            final Acceleration accelerationBiasZ) {
        setAccelerationBiasX(accelerationBiasX);
        setAccelerationBiasY(accelerationBiasY);
        setAccelerationBiasZ(accelerationBiasZ);
    }

    /**
     * Gets estimated gyroscope bias resolved around x axis.
     *
     * @param result instance where estimated gyroscope bias resolved around x axis will
     *               be stored.
     */
    public void getAngularSpeedGyroBiasX(final AngularSpeed result) {
        result.setValue(gyroBiasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets estimated gyroscope bias resolved around x axis.
     *
     * @return estimated gyroscope bias resolved around x axis.
     */
    public AngularSpeed getAngularSpeedGyroBiasX() {
        return new AngularSpeed(gyroBiasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets estimated gyroscope bias resolved around x axis.
     *
     * @param gyroBiasX estimated gyroscope bias resolved around x axis.
     */
    public void setGyroBiasX(final AngularSpeed gyroBiasX) {
        this.gyroBiasX = AngularSpeedConverter.convert(gyroBiasX.getValue().doubleValue(), gyroBiasX.getUnit(),
                AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets estimated gyroscope bias resolved around y axis.
     *
     * @param result instance where estimated gyroscope bias resolved around y axis will
     *               be stored.
     */
    public void getAngularSpeedGyroBiasY(final AngularSpeed result) {
        result.setValue(gyroBiasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets estimated gyroscope bias resolved around y axis.
     *
     * @return estimated gyroscope bias resolved around y axis.
     */
    public AngularSpeed getAngularSpeedGyroBiasY() {
        return new AngularSpeed(gyroBiasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets estimated gyroscope bias resolved around y axis.
     *
     * @param gyroBiasY estimated gyroscope bias resolved around y axis.
     */
    public void setGyroBiasY(final AngularSpeed gyroBiasY) {
        this.gyroBiasY = AngularSpeedConverter.convert(gyroBiasY.getValue().doubleValue(), gyroBiasY.getUnit(),
                AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets estimated gyroscope bias resolved around z axis.
     *
     * @param result instance where estimated gyroscope bias resolved around z axis will
     *               be stored.
     */
    public void getAngularSpeedGyroBiasZ(final AngularSpeed result) {
        result.setValue(gyroBiasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets estimated gyroscope bias resolved around z axis.
     *
     * @return estimated gyroscope bias resolved around z axis.
     */
    public AngularSpeed getAngularSpeedGyroBiasZ() {
        return new AngularSpeed(gyroBiasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets estimated gyroscope bias resolved around z axis.
     *
     * @param gyroBiasZ estimated gyroscope bias resolved around z axis.
     */
    public void setGyroBiasZ(final AngularSpeed gyroBiasZ) {
        this.gyroBiasZ = AngularSpeedConverter.convert(gyroBiasZ.getValue().doubleValue(), gyroBiasZ.getUnit(),
                AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets estimated gyroscope bias coordinates.
     *
     * @param gyroBiasX estimated gyroscope bias resolved around x axis.
     * @param gyroBiasY estimated gyroscope bias resolved around y axis.
     * @param gyroBiasZ estimated gyroscope bias resolved around z axis.
     */
    public void setGyroBiasCoordinates(
            final AngularSpeed gyroBiasX, final AngularSpeed gyroBiasY, final AngularSpeed gyroBiasZ) {
        setGyroBiasX(gyroBiasX);
        setGyroBiasY(gyroBiasY);
        setGyroBiasZ(gyroBiasZ);
    }

    /**
     * Copies this instance data into provided instance.
     *
     * @param output destination instance where data will be copied to.
     */
    public void copyTo(final INSLooselyCoupledKalmanState output) {

initialBiasX = convertAcceleration(initialBias.getValueX(), initialBias.getUnit());
        initialBiasY = convertAcceleration(initialBias.getValueY(), initialBias.getUnit());
        initialBiasZ = convertAcceleration(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(final double initialSx, final double initialSy, final double initialSz)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial bias to be used to find a solution as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of initial bias.
     */
    @Override
    public double[] getInitialBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial bias to be used to find a solution as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial bias to be used to find a solution as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial bias to be used to find a solution as a column matrix.
     * Values are expressed in meters per squared second (m/s^2).
     *
     * @return initial bias to be used to find a solution as a column matrix.
     */
    @Override
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial bias to be used to find a solution as a column matrix.
     * Values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial bias to be used to find a solution as a column matrix with
     * values expressed in meters per squared second (m/s^2).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

final double[] result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @return initial gyroscope bias to be used to find a solution as a
     * column matrix.
     */
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * a column matrix with values expressed in radians per second (rad/s).
     *
     * @param initialBias initial gyroscope bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @return initial bias coordinates.
     */
    public AngularSpeedTriad getInitialBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    public void getInitialBiasAsTriad(final AngularSpeedTriad result) {
        result.setValueCoordinatesAndUnit(initialBiasX, initialBiasY, initialBiasZ,
                AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBias initial bias coordinates to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(final AngularSpeedTriad initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialBiasX = convertAngularSpeed(initialBias.getValueX(), initialBias.getUnit());
        initialBiasY = convertAngularSpeed(initialBias.getValueY(), initialBias.getUnit());
        initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {

        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @return constant rotation rate of turntable.
     */
    public double getTurntableRotationRate() {
        return turntableRotationRate;
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final double turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (turntableRotationRate <= 0.0) {
            throw new IllegalArgumentException();
        }

        this.turntableRotationRate = turntableRotationRate;
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @return constant rotation rate of turntable.
     */
    public AngularSpeed getTurntableRotationRateAsAngularSpeed() {
        return new AngularSpeed(turntableRotationRate, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @param result instance where result will be stored.
     */
    public void getTurntableRotationRateAsAngularSpeed(final AngularSpeed result) {
        result.setValue(turntableRotationRate);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final AngularSpeed turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTurntableRotationRate(convertAngularSpeed(turntableRotationRate));
    }

    /**
     * Gets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @return time interval between measurements.
     */
    public double getTimeInterval() {
        return timeInterval;
    }

    /**
     * Sets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTimeInterval(final double timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (timeInterval <= 0.0) {
            throw new IllegalArgumentException();
        }
        this.timeInterval = timeInterval;
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @return time interval between measurements.
     */
    public Time getTimeIntervalAsTime() {
        return new Time(timeInterval, TimeUnit.SECOND);
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @param result instance where result will be stored.
     */
    public void getTimeIntervalAsTime(final Time result) {
        result.setValue(timeInterval);
        result.setUnit(TimeUnit.SECOND);
    }

    /**
     * Sets time interval between measurements being captured.
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTimeInterval(final Time timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTimeInterval(convertTime(timeInterval));
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public List<StandardDeviationBodyKinematics> getMeasurements() {

public void setListener(final KnownBiasAndFrameGyroscopeLinearLeastSquaresCalibratorListener listener)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets known x coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @return x coordinate of gyroscope bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets known x coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @param biasX x coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets known y coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @return y coordinate of gyroscope bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets known y coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @param biasY y coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = biasY;
    }

    /**
     * Gets known z coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @return z coordinate of gyroscope bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets known z coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @param biasZ z coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = biasZ;
    }

    /**
     * Gets known x coordinate of gyroscope bias.
     *
     * @return x coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedX() {
        return new AngularSpeed(biasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets known x coordinate of gyroscope bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(biasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known x coordinate of gyroscope bias.
     *
     * @param biasX x coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final AngularSpeed biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasX = convertAngularSpeed(biasX);
    }

    /**
     * Gets known y coordinate of gyroscope bias.
     *
     * @return y coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedY() {
        return new AngularSpeed(biasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets known y coordinate of gyroscope bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(biasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known y coordinate of gyroscope bias.
     *
     * @param biasY y coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final AngularSpeed biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasY = convertAngularSpeed(biasY);
    }

    /**
     * Gets known z coordinate of gyroscope bias.
     *
     * @return z coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedZ() {
        return new AngularSpeed(biasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets known z coordinate of gyroscope bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(biasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known z coordinate of gyroscope bias.
     *
     * @param biasZ z coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final AngularSpeed biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasZ = convertAngularSpeed(biasZ);
    }

    /**
     * Sets known gyroscope bias coordinates expressed in radians per second
     * (rad/s).
     *
     * @param biasX x coordinate of gyroscope bias.
     * @param biasY y coordinate of gyroscope bias.
     * @param biasZ z coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasX = biasX;
        this.biasY = biasY;
        this.biasZ = biasZ;
    }

    /**
     * Sets known gyroscope bias coordinates.
     *
     * @param biasX x coordinate of gyroscope bias.
     * @param biasY y coordinate of gyroscope bias.
     * @param biasZ z coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final AngularSpeed biasX, final AngularSpeed biasY, final AngularSpeed biasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasX = convertAngularSpeed(biasX);
        this.biasY = convertAngularSpeed(biasY);
        this.biasZ = convertAngularSpeed(biasZ);
    }

    /**
     * Gets known gyroscope bias.
     *
     * @return known gyroscope bias.
     */
    public AngularSpeedTriad getBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known gyroscope bias.
     *
     * @param result instance where result will be stored.
     */
    public void getBiasAsTriad(final AngularSpeedTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known gyroscope bias.
     *
     * @param bias gyroscope bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setBias(final AngularSpeedTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAngularSpeed(bias.getValueX(), bias.getUnit());
        biasY = convertAngularSpeed(bias.getValueY(), bias.getUnit());
        biasZ = convertAngularSpeed(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets known gyroscope bias as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinate of known bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets known gyroscope bias as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets known gyroscope bias as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param bias known gyroscope bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (bias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        biasX = bias[0];
        biasY = bias[1];
        biasZ = bias[2];
    }

    /**
     * Gets known gyroscope bias as a column matrix.
     *
     * @return known gyroscope bias as a column matrix.
     */
    @Override
    public Matrix getBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known gyroscope bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, biasX);
        result.setElementAtIndex(1, biasY);
        result.setElementAtIndex(2, biasZ);
    }

    /**
     * Sets known gyroscope bias as a column matrix.
     *
     * @param bias gyroscope bias to be set.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setBias(final Matrix bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (bias.getRows() != BodyKinematics.COMPONENTS || bias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        biasX = bias.getElementAtIndex(0);
        biasY = bias.getElementAtIndex(1);
        biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurementsOrSequences() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start the calibration.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Estimates gyroscope calibration parameters containing bias, scale factors,
     * cross-coupling errors and g-dependant cross biases.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if calibration fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }

        if (!isReady()) {
            throw new NotReadyException();
        }

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            if (commonAxisUsed) {
                calibrateCommonAxis();
            } else {
                calibrateGeneral();
            }

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final AlgebraException e) {

public void setBias(final Acceleration biasX, final Acceleration biasY, final Acceleration biasZ) {
        setBiasX(biasX);
        setBiasY(biasY);
        setBiasZ(biasZ);
    }

    /**
     * Gets cross coupling errors matrix.
     *
     * @return cross coupling errors matrix.
     */
    public Matrix getCrossCouplingErrors() {
        return new Matrix(crossCouplingErrors);
    }

    /**
     * Gets cross coupling errors matrix.
     *
     * @param result instance where result will be stored.
     */
    public void getCrossCouplingErrors(final Matrix result) {
        crossCouplingErrors.copyTo(result);
    }

    /**
     * Sets cross coupling errors matrix.
     *
     * @param crossCouplingErrors cross coupling errors matrix. Must be 3x3.
     * @throws AlgebraException         if provided matrix cannot be inverted.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    public void setCrossCouplingErrors(final Matrix crossCouplingErrors) throws AlgebraException {
        if (crossCouplingErrors.getRows() != BodyKinematics.COMPONENTS
                || crossCouplingErrors.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        this.crossCouplingErrors = crossCouplingErrors;

        identity.add(crossCouplingErrors, tmp1);

        Utils.inverse(tmp1, tmp2);
    }

    /**
     * Gets x scaling factor.
     *
     * @return x scaling factor.
     */
    public double getSx() {
        return crossCouplingErrors.getElementAt(0, 0);
    }

    /**
     * Sets x scaling factor
     *
     * @param sx x scaling factor.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setSx(final double sx) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 0, sx);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets y scaling factor.
     *
     * @return y scaling factor.
     */
    public double getSy() {
        return crossCouplingErrors.getElementAt(1, 1);
    }

    /**
     * Sets y scaling factor.
     *
     * @param sy y scaling factor.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setSy(final double sy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(1, 1, sy);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets z scaling factor.
     *
     * @return z scaling factor.
     */
    public double getSz() {
        return crossCouplingErrors.getElementAt(2, 2);
    }

    /**
     * Sets z scaling factor.
     *
     * @param sz z scaling factor.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setSz(final double sz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(2, 2, sz);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets x-y cross coupling error.
     *
     * @return x-y cross coupling error.
     */
    public double getMxy() {
        return crossCouplingErrors.getElementAt(0, 1);
    }

    /**
     * Sets x-y cross coupling error.
     *
     * @param mxy x-y cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMxy(final double mxy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 1, mxy);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets x-z cross coupling error.
     *
     * @return x-z cross coupling error.
     */
    public double getMxz() {
        return crossCouplingErrors.getElementAt(0, 2);
    }

    /**
     * Sets x-z cross coupling error.
     *
     * @param mxz x-z cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMxz(final double mxz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 2, mxz);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets y-x cross coupling error.
     *
     * @return y-x cross coupling error.
     */
    public double getMyx() {
        return crossCouplingErrors.getElementAt(1, 0);
    }

    /**
     * Sets y-x cross coupling error.
     *
     * @param myx y-x cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMyx(final double myx) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(1, 0, myx);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets y-z cross coupling error.
     *
     * @return y-z cross coupling error.
     */
    public double getMyz() {
        return crossCouplingErrors.getElementAt(1, 2);
    }

    /**
     * Sets y-z cross coupling error.
     *
     * @param myz y-z cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMyz(final double myz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(1, 2, myz);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets z-x cross coupling error.
     *
     * @return z-x cross coupling error.
     */
    public double getMzx() {
        return crossCouplingErrors.getElementAt(2, 0);
    }

    /**
     * Sets z-x cross coupling error.
     *
     * @param mzx z-x cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMzx(final double mzx) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(2, 0, mzx);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets z-y cross coupling error.
     *
     * @return z-y cross coupling error.
     */
    public double getMzy() {
        return crossCouplingErrors.getElementAt(2, 1);
    }

    /**
     * Sets z-y cross coupling error.
     *
     * @param mzy z-y cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMzy(final double mzy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(2, 1, mzy);
        setCrossCouplingErrors(m);
    }

    /**
     * Sets scaling factors.
     *
     * @param sx x scaling factor.
     * @param sy y scaling factor.
     * @param sz z scaling factor.
     * @throws AlgebraException if provided values make cross coupling matrix
     *                          non invertible.
     */
    public void setScalingFactors(final double sx, final double sy, final double sz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 0, sx);
        m.setElementAt(1, 1, sy);
        m.setElementAt(2, 2, sz);
        setCrossCouplingErrors(m);
    }

    /**
     * Sets cross coupling errors.
     *
     * @param mxy x-y cross coupling error.
     * @param mxz x-z cross coupling error.
     * @param myx y-x cross coupling error.
     * @param myz y-z cross coupling error.
     * @param mzx z-x cross coupling error.
     * @param mzy z-y cross coupling error.
     * @throws AlgebraException if provided values make cross coupling matrix
     *                          non invertible.
     */
    public void setCrossCouplingErrors(
            final double mxy, final double mxz, final double myx,
            final double myz, final double mzx, final double mzy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 1, mxy);
        m.setElementAt(0, 2, mxz);
        m.setElementAt(1, 0, myx);
        m.setElementAt(1, 2, myz);
        m.setElementAt(2, 0, mzx);
        m.setElementAt(2, 1, mzy);
        setCrossCouplingErrors(m);
    }

    /**
     * Sets scaling factors and cross coupling errors.
     *
     * @param sx  x scaling factor.
     * @param sy  y scaling factor.
     * @param sz  z scaling factor.
     * @param mxy x-y cross coupling error.
     * @param mxz x-z cross coupling error.
     * @param myx y-x cross coupling error.
     * @param myz y-z cross coupling error.
     * @param mzx z-x cross coupling error.
     * @param mzy z-y cross coupling error.
     * @throws AlgebraException if provided values make cross coupling matrix
     *                          non invertible.
     */
    public void setScalingFactorsAndCrossCouplingErrors(
            final double sx, final double sy, final double sz,
            final double mxy, final double mxz, final double myx,
            final double myz, final double mzx, final double mzy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 0, sx);
        m.setElementAt(1, 1, sy);
        m.setElementAt(2, 2, sz);
        m.setElementAt(0, 1, mxy);
        m.setElementAt(0, 2, mxz);
        m.setElementAt(1, 0, myx);
        m.setElementAt(1, 2, myz);
        m.setElementAt(2, 0, mzx);
        m.setElementAt(2, 1, mzy);
        setCrossCouplingErrors(m);
    }

    /**
     * Fixes provided measured specific force values by undoing the errors
     * introduced by the accelerometer model to restore the true specific
     * force.
     * This method uses last provided bias and cross coupling errors.
     *
     * @param measuredF measured specific force.
     * @param result    instance where restored true specific force will be stored.
     *                  Mut have length 3.
     * @throws AlgebraException         if there are numerical instabilities.
     * @throws IllegalArgumentException if length of provided result array is
     *                                  not 3.
     */
    public void fix(final AccelerationTriad measuredF, final double[] result) throws AlgebraException {

setInputData();

        fitter.fit();

        final var result = fitter.getA();

        final var m11 = result[0];
        final var m21 = result[1];
        final var m31 = result[2];

        final var m12 = result[3];
        final var m22 = result[4];
        final var m32 = result[5];

        final var m13 = result[6];
        final var m23 = result[7];
        final var m33 = result[8];

        final var g11 = result[9];
        final var g21 = result[10];
        final var g31 = result[11];

        final var g12 = result[12];
        final var g22 = result[13];
        final var g32 = result[14];

        final var g13 = result[15];
        final var g23 = result[16];
        final var g33 = result[17];

        final var mm = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        mm.setElementAtIndex(0, m11);
        mm.setElementAtIndex(1, m21);
        mm.setElementAtIndex(2, m31);

        mm.setElementAtIndex(3, m12);
        mm.setElementAtIndex(4, m22);
        mm.setElementAtIndex(5, m32);

        mm.setElementAtIndex(6, m13);
        mm.setElementAtIndex(7, m23);
        mm.setElementAtIndex(8, m33);

        final var mg = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        mg.setElementAtIndex(0, g11);
        mg.setElementAtIndex(1, g21);
        mg.setElementAtIndex(2, g31);

        mg.setElementAtIndex(3, g12);
        mg.setElementAtIndex(4, g22);
        mg.setElementAtIndex(5, g32);

        mg.setElementAtIndex(6, g13);
        mg.setElementAtIndex(7, g23);
        mg.setElementAtIndex(8, g33);

        setResult(mm, mg);

        // at this point covariance is expressed in terms of M and G, and must
        // be expressed in terms of Mg and Gg.
        // We know that:
        // Mg = M - I
        // Gg = M * G

        // M = [m11  m12  m13]
        //     [m21  m22  m23]
        //     [m31  m32  m33]

        // G = [g11  g12  g13]
        //     [g21  g22  g23]
        //     [g31  g32  g33]

        // Mg = [sx  mxy  mxz] = [m11 - 1    m12         m13     ]
        //      [myx sy	  myz]   [m21        m22 - 1     m23     ]
        //      [mzx mzy  sz ]   [m31        m32         m33 - 1 ]

        // Gg = [gg11  gg12  gg13] = [m11  m12  m13][g11  g12  g13]
        //      [gg21  gg22  gg23]   [m21  m22  m23][g21  g22  g23]
        //      [gg31  gg32  gg33]   [m31  m32  m33][g31  g32  g33]

        // Defining the linear application:
        // F(M, G) = F(m11, m21, m31, m12, m22, m32, m13, m23, m33, g11, g21, g31, g12, g22, g32, g13, g23, g33)
        // as:
        // [sx] =   [m11 - 1]
        // [sy]     [m22 - 1]
        // [sz]     [m33 - 1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [m21]
        // [myz]    [m23]
        // [mzx]    [m31]
        // [mzy]    [m32]
        // [gg11]   [m11 * g11 + m12 * g21 + m13 * g31]
        // [gg21]   [m21 * g11 + m22 * g21 + m23 * g31]
        // [gg31]   [m31 * g11 + m32 * g21 + m33 * g31]
        // [gg12]   [m11 * g12 + m12 * g22 + m13 * g32]
        // [gg22]   [m21 * g12 + m22 * g22 + n23 * g32]
        // [gg32]   [m31 * g12 + m32 * g22 + m33 * g32]
        // [gg13]   [m11 * g13 + m12 * g23 + m13 * g33]
        // [gg23]   [m21 * g13 + m22 * g23 + m23 * g33]
        // [gg33]   [m31 * g13 + m32 * g23 + m33 * g33]

        // Then the Jacobian of F(M, G) is:
        // J = [1    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [g11  0    0    g21  0    0    g31  0    0    m11  m12  m13  0    0    0    0    0    0  ]
        //     [0    g11  0    0    g21  0    0    g31  0    m21  m22  m23  0    0    0    0    0    0  ]
        //     [0    0    g11  0    0    g21  0    0    g31  m31  m32  m33  0    0    0    0    0    0  ]
        //     [g12  0    0    g22  0    0    g32  0    0    0    0    0    m11  m12  m13  0    0    0  ]
        //     [0    g12  0    0    g22  0    0    g32  0    0    0    0    m21  m22  m23  0    0    0  ]
        //     [0    0    g12  0    0    g22  0    0    g32  0    0    0    m31  m32  m33  0    0    0  ]
        //     [g13  0    0    g23  0    0    g33  0    0    0    0    0    0    0    0    m11  m12  m13]
        //     [0    g13  0    0    g23  0    0    g33  0    0    0    0    0    0    0    m21  m22  m23]
        //     [0    0    g13  0    0    g23  0    0    g33  0    0    0    0    0    0    m31  m32  m33]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS_AND_CROSS_BIASES, GENERAL_UNKNOWNS_AND_CROSS_BIASES);

        jacobian.setElementAt(0, 0, 1.0);
        jacobian.setElementAt(1, 4, 1.0);
        jacobian.setElementAt(2, 8, 1.0);

        jacobian.setElementAt(3, 3, 1.0);
        jacobian.setElementAt(4, 6, 1.0);
        jacobian.setElementAt(5, 1, 1.0);

        jacobian.setElementAt(6, 7, 1.0);
        jacobian.setElementAt(7, 2, 1.0);
        jacobian.setElementAt(8, 5, 1.9);

        jacobian.setElementAt(9, 0, g11);
        jacobian.setElementAt(9, 3, g21);
        jacobian.setElementAt(9, 6, g31);
        jacobian.setElementAt(9, 9, m11);
        jacobian.setElementAt(9, 10, m12);
        jacobian.setElementAt(9, 11, m13);

        jacobian.setElementAt(10, 1, g11);
        jacobian.setElementAt(10, 4, g21);
        jacobian.setElementAt(10, 7, g31);
        jacobian.setElementAt(10, 9, m21);
        jacobian.setElementAt(10, 10, m22);
        jacobian.setElementAt(10, 11, m23);

        jacobian.setElementAt(11, 2, g11);
        jacobian.setElementAt(11, 5, g21);
        jacobian.setElementAt(11, 8, g31);
        jacobian.setElementAt(11, 9, m31);
        jacobian.setElementAt(11, 10, m32);
        jacobian.setElementAt(11, 11, m33);

        jacobian.setElementAt(12, 0, g12);
        jacobian.setElementAt(12, 3, g22);
        jacobian.setElementAt(12, 6, g32);
        jacobian.setElementAt(12, 12, m11);
        jacobian.setElementAt(12, 13, m12);
        jacobian.setElementAt(12, 14, m13);

        jacobian.setElementAt(13, 1, g12);
        jacobian.setElementAt(13, 4, g22);
        jacobian.setElementAt(13, 7, g32);
        jacobian.setElementAt(13, 12, m21);
        jacobian.setElementAt(13, 13, m22);
        jacobian.setElementAt(13, 14, m23);

        jacobian.setElementAt(14, 2, g12);
        jacobian.setElementAt(14, 5, g22);
        jacobian.setElementAt(14, 8, g32);
        jacobian.setElementAt(14, 12, m31);
        jacobian.setElementAt(14, 13, m32);
        jacobian.setElementAt(14, 14, m33);

        jacobian.setElementAt(15, 0, g13);
        jacobian.setElementAt(15, 3, g23);
        jacobian.setElementAt(15, 6, g33);
        jacobian.setElementAt(15, 15, m11);
        jacobian.setElementAt(15, 16, m12);
        jacobian.setElementAt(15, 17, m13);

        jacobian.setElementAt(16, 1, g13);
        jacobian.setElementAt(16, 4, g23);
        jacobian.setElementAt(16, 7, g33);
        jacobian.setElementAt(16, 15, m21);
        jacobian.setElementAt(16, 16, m22);
        jacobian.setElementAt(16, 17, m23);

        jacobian.setElementAt(17, 2, g13);
        jacobian.setElementAt(17, 5, g23);
        jacobian.setElementAt(17, 8, g33);
        jacobian.setElementAt(17, 15, m31);
        jacobian.setElementAt(17, 16, m32);
        jacobian.setElementAt(17, 17, m33);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed
     * for both the accelerometer and gyroscope and G-dependent cross biases
     * are ignored.
     *
     * @throws AlgebraException                         if accelerometer parameters prevent fixing
     *                                                  measured accelerometer values due to numerical instabilities.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateCommonAxis() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {

return sequences != null && sequences.size() >= getMinimumRequiredMeasurementsOrSequences();
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where estimated gyroscope biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return column matrix containing x,y,z components of estimated gyroscope
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasX() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasY() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasZ() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedX() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[0], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedX(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedY() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[1], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedY(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedZ() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedZ(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @return estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeedTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated gyroscope bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AngularSpeedTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bgx, bgy, bgz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32,
     * gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {

}

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where estimated gyroscope biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return column matrix containing x,y,z components of estimated gyroscope
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasX() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasY() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasZ() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedX() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[0], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedX(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedY() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[1], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedY(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedZ() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedZ(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @return estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeedTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated gyroscope bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AngularSpeedTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bgx, bgy, bgz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32,
     * gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {

}

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz,
            final double initialMyx, final double initialMyz,
            final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public Collection<StandardDeviationFrameBodyKinematics> getMeasurements() {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @return constant rotation rate of turntable.
     */
    public double getTurntableRotationRate() {
        return turntableRotationRate;
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final double turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (turntableRotationRate <= 0.0) {
            throw new IllegalArgumentException();
        }

        this.turntableRotationRate = turntableRotationRate;
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @return constant rotation rate of turntable.
     */
    public AngularSpeed getTurntableRotationRateAsAngularSpeed() {
        return new AngularSpeed(turntableRotationRate, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @param result instance where result will be stored.
     */
    public void getTurntableRotationRateAsAngularSpeed(final AngularSpeed result) {
        result.setValue(turntableRotationRate);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final AngularSpeed turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTurntableRotationRate(convertAngularSpeed(turntableRotationRate));
    }

    /**
     * Gets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @return time interval between measurements.
     */
    public double getTimeInterval() {
        return timeInterval;
    }

    /**
     * Sets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTimeInterval(final double timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (timeInterval <= 0.0) {
            throw new IllegalArgumentException();
        }
        this.timeInterval = timeInterval;
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @return time interval between measurements.
     */
    public Time getTimeIntervalAsTime() {
        return new Time(timeInterval, TimeUnit.SECOND);
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @param result instance where result will be stored.
     */
    public void getTimeIntervalAsTime(final Time result) {
        result.setValue(timeInterval);
        result.setUnit(TimeUnit.SECOND);
    }

    /**
     * Sets time interval between measurements being captured.
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTimeInterval(final Time timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTimeInterval(convertTime(timeInterval));
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyKinematics> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @param measurements collection of body kinematics measurements at a
     *                     known position with unknown orientations.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final Collection<StandardDeviationBodyKinematics> measurements) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * ECEF coordinates.
     *
     * @return position where body kinematics measures have been taken.
     */
    public ECEFPosition getEcefPosition() {
        return position;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * ECEF coordinates.
     *
     * @param position position where body kinematics measures have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final ECEFPosition position) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.position = position;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @return position where body kinematics measures have been taken or null if
     * not available.
     */
    public NEDPosition getNedPosition() {
        final var result = new NEDPosition();
        return getNedPosition(result) ? result : null;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if NED position could be computed, false otherwise.
     */
    public boolean getNedPosition(final NEDPosition result) {
        if (position != null) {
            final var velocity = new NEDVelocity();
            ECEFtoNEDPositionVelocityConverter.convertECEFtoNED(
                    position.getX(), position.getY(), position.getZ(), 0.0, 0.0, 0.0, result, velocity);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Sets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @param position position where body kinematics measures have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final NEDPosition position) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.position = convertPosition(position);
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.STANDARD_DEVIATION_BODY_KINEMATICS_MEASUREMENT;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return false;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement/sequence or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return false;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Indicates whether G-dependent cross biases are being estimated
     * or not.
     * When enabled, this adds 9 variables from Gg matrix.
     *
     * @return true if G-dependent cross biases will be estimated,
     * false otherwise.
     */
    public boolean isGDependentCrossBiasesEstimated() {
        return estimateGDependentCrossBiases;
    }

    /**
     * Specifies whether G-dependent cross biases are being estimated
     * or not.
     * When enabled, this adds 9 variables from Gg matrix.
     *
     * @param estimateGDependentCrossBiases true if G-dependent cross
     *                                      biases will be estimated,
     *                                      false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setGDependentCrossBiasesEstimated(final boolean estimateGDependentCrossBiases) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.estimateGDependentCrossBiases = estimateGDependentCrossBiases;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    public KnownBiasTurntableGyroscopeCalibratorListener getListener() {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @return constant rotation rate of turntable.
     */
    public double getTurntableRotationRate() {
        return turntableRotationRate;
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(
            final double turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (turntableRotationRate <= 0.0) {
            throw new IllegalArgumentException();
        }

        this.turntableRotationRate = turntableRotationRate;
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @return constant rotation rate of turntable.
     */
    public AngularSpeed getTurntableRotationRateAsAngularSpeed() {
        return new AngularSpeed(turntableRotationRate, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @param result instance where result will be stored.
     */
    public void getTurntableRotationRateAsAngularSpeed(final AngularSpeed result) {
        result.setValue(turntableRotationRate);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final AngularSpeed turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTurntableRotationRate(convertAngularSpeed(turntableRotationRate));
    }

    /**
     * Gets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @return time interval between measurements.
     */
    public double getTimeInterval() {
        return timeInterval;
    }

    /**
     * Sets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTimeInterval(final double timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (timeInterval <= 0.0) {
            throw new IllegalArgumentException();
        }
        this.timeInterval = timeInterval;
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @return time interval between measurements.
     */
    public Time getTimeIntervalAsTime() {
        return new Time(timeInterval, TimeUnit.SECOND);
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @param result instance where result will be stored.
     */
    public void getTimeIntervalAsTime(final Time result) {
        result.setValue(timeInterval);
        result.setUnit(TimeUnit.SECOND);
    }

    /**
     * Sets time interval between measurements being captured.
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTimeInterval(final Time timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTimeInterval(convertTime(timeInterval));
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public List<StandardDeviationBodyKinematics> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @param measurements collection of body kinematics measurements at a
     *                     known position with unknown orientations.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final List<StandardDeviationBodyKinematics> measurements) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * ECEF coordinates.
     *
     * @return position where body kinematics measures have been taken.
     */
    public ECEFPosition getEcefPosition() {
        return position;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * ECEF coordinates.
     *
     * @param position position where body kinematics measures have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final ECEFPosition position) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.position = position;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @return position where body kinematics measures have been taken or null if
     * not available.
     */
    public NEDPosition getNedPosition() {
        final var result = new NEDPosition();
        return getNedPosition(result) ? result : null;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if NED position could be computed, false otherwise.
     */
    public boolean getNedPosition(final NEDPosition result) {

        if (position != null) {
            final var velocity = new NEDVelocity();
            ECEFtoNEDPositionVelocityConverter.convertECEFtoNED(
                    position.getX(), position.getY(), position.getZ(), 0.0, 0.0, 0.0, result, velocity);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Sets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @param position position where body kinematics measures have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final NEDPosition position) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.position = convertPosition(position);
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.STANDARD_DEVIATION_BODY_KINEMATICS_MEASUREMENT;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return true;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Indicates whether G-dependent cross biases are being estimated
     * or not.
     * When enabled, this adds 9 variables from Gg matrix.
     *
     * @return true if G-dependent cross biases will be estimated,
     * false otherwise.
     */
    public boolean isGDependentCrossBiasesEstimated() {
        return estimateGDependentCrossBiases;
    }

    /**
     * Specifies whether G-dependent cross biases are being estimated
     * or not.
     * When enabled, this adds 9 variables from Gg matrix.
     *
     * @param estimateGDependentCrossBiases true if G-dependent cross
     *                                      biases will be estimated,
     *                                      false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setGDependentCrossBiasesEstimated(final boolean estimateGDependentCrossBiases) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.estimateGDependentCrossBiases = estimateGDependentCrossBiases;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    public RobustKnownBiasTurntableGyroscopeCalibratorListener getListener() {

|| crossCouplingErrors.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        this.crossCouplingErrors = crossCouplingErrors;

        identity.add(crossCouplingErrors, tmp1);

        Utils.inverse(tmp1, tmp2);
    }

    /**
     * Gets x scaling factor.
     *
     * @return x scaling factor.
     */
    public double getSx() {
        return crossCouplingErrors.getElementAt(0, 0);
    }

    /**
     * Sets x scaling factor
     *
     * @param sx x scaling factor.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setSx(final double sx) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 0, sx);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets y scaling factor.
     *
     * @return y scaling factor.
     */
    public double getSy() {
        return crossCouplingErrors.getElementAt(1, 1);
    }

    /**
     * Sets y scaling factor.
     *
     * @param sy y scaling factor.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setSy(final double sy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(1, 1, sy);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets z scaling factor.
     *
     * @return z scaling factor.
     */
    public double getSz() {
        return crossCouplingErrors.getElementAt(2, 2);
    }

    /**
     * Sets z scaling factor.
     *
     * @param sz z scaling factor.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setSz(final double sz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(2, 2, sz);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets x-y cross coupling error.
     *
     * @return x-y cross coupling error.
     */
    public double getMxy() {
        return crossCouplingErrors.getElementAt(0, 1);
    }

    /**
     * Sets x-y cross coupling error.
     *
     * @param mxy x-y cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMxy(final double mxy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 1, mxy);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets x-z cross coupling error.
     *
     * @return x-z cross coupling error.
     */
    public double getMxz() {
        return crossCouplingErrors.getElementAt(0, 2);
    }

    /**
     * Sets x-z cross coupling error.
     *
     * @param mxz x-z cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMxz(final double mxz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 2, mxz);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets y-x cross coupling error.
     *
     * @return y-x cross coupling error.
     */
    public double getMyx() {
        return crossCouplingErrors.getElementAt(1, 0);
    }

    /**
     * Sets y-x cross coupling error.
     *
     * @param myx y-x cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMyx(final double myx) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(1, 0, myx);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets y-z cross coupling error.
     *
     * @return y-z cross coupling error.
     */
    public double getMyz() {
        return crossCouplingErrors.getElementAt(1, 2);
    }

    /**
     * Sets y-z cross coupling error.
     *
     * @param myz y-z cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMyz(final double myz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(1, 2, myz);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets z-x cross coupling error.
     *
     * @return z-x cross coupling error.
     */
    public double getMzx() {
        return crossCouplingErrors.getElementAt(2, 0);
    }

    /**
     * Sets z-x cross coupling error.
     *
     * @param mzx z-x cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMzx(final double mzx) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(2, 0, mzx);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets z-y cross coupling error.
     *
     * @return z-y cross coupling error.
     */
    public double getMzy() {
        return crossCouplingErrors.getElementAt(2, 1);
    }

    /**
     * Sets z-y cross coupling error.
     *
     * @param mzy z-y cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non invertible.
     */
    public void setMzy(final double mzy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(2, 1, mzy);
        setCrossCouplingErrors(m);
    }

    /**
     * Sets scaling factors.
     *
     * @param sx x scaling factor.
     * @param sy y scaling factor.
     * @param sz z scaling factor.
     * @throws AlgebraException if provided values make cross coupling matrix
     *                          non invertible.
     */
    public void setScalingFactors(final double sx, final double sy, final double sz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 0, sx);
        m.setElementAt(1, 1, sy);
        m.setElementAt(2, 2, sz);
        setCrossCouplingErrors(m);
    }

    /**
     * Sets cross coupling errors.
     *
     * @param mxy x-y cross coupling error.
     * @param mxz x-z cross coupling error.
     * @param myx y-x cross coupling error.
     * @param myz y-z cross coupling error.
     * @param mzx z-x cross coupling error.
     * @param mzy z-y cross coupling error.
     * @throws AlgebraException if provided values make cross coupling matrix
     *                          non invertible.
     */
    public void setCrossCouplingErrors(
            final double mxy, final double mxz, final double myx,
            final double myz, final double mzx, final double mzy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 1, mxy);
        m.setElementAt(0, 2, mxz);
        m.setElementAt(1, 0, myx);
        m.setElementAt(1, 2, myz);
        m.setElementAt(2, 0, mzx);
        m.setElementAt(2, 1, mzy);
        setCrossCouplingErrors(m);
    }

    /**
     * Sets scaling factors and cross coupling errors.
     *
     * @param sx  x scaling factor.
     * @param sy  y scaling factor.
     * @param sz  z scaling factor.
     * @param mxy x-y cross coupling error.
     * @param mxz x-z cross coupling error.
     * @param myx y-x cross coupling error.
     * @param myz y-z cross coupling error.
     * @param mzx z-x cross coupling error.
     * @param mzy z-y cross coupling error.
     * @throws AlgebraException if provided values make cross coupling matrix
     *                          non invertible.
     */
    public void setScalingFactorsAndCrossCouplingErrors(
            final double sx, final double sy, final double sz,
            final double mxy, final double mxz, final double myx,
            final double myz, final double mzx, final double mzy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 0, sx);
        m.setElementAt(1, 1, sy);
        m.setElementAt(2, 2, sz);
        m.setElementAt(0, 1, mxy);
        m.setElementAt(0, 2, mxz);
        m.setElementAt(1, 0, myx);
        m.setElementAt(1, 2, myz);
        m.setElementAt(2, 0, mzx);
        m.setElementAt(2, 1, mzy);
        setCrossCouplingErrors(m);
    }

    /**
     * Fixes provided measured specific force values by undoing the errors
     * introduced by the accelerometer model to restore the true specific
     * force.
     * This method uses last provided bias and cross coupling errors.
     *
     * @param measuredF measured specific force.
     * @param result    instance where restored true specific force will be stored.
     *                  Mut have length 3.
     * @throws AlgebraException         if there are numerical instabilities.
     * @throws IllegalArgumentException if length of provided result array is
     *                                  not 3.
     */
    public void fix(final AccelerationTriad measuredF, final double[] result) throws AlgebraException {

|| crossCouplingErrors.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        this.crossCouplingErrors = crossCouplingErrors;

        identity.add(crossCouplingErrors, tmp1);

        Utils.inverse(tmp1, tmp2);
    }

    /**
     * Gets x scaling factor.
     *
     * @return x scaling factor.
     */
    public double getSx() {
        return crossCouplingErrors.getElementAt(0, 0);
    }

    /**
     * Sets x scaling factor
     *
     * @param sx x scaling factor.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non-invertible.
     */
    public void setSx(final double sx) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 0, sx);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets y scaling factor.
     *
     * @return y scaling factor.
     */
    public double getSy() {
        return crossCouplingErrors.getElementAt(1, 1);
    }

    /**
     * Sets y scaling factor.
     *
     * @param sy y scaling factor.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non-invertible.
     */
    public void setSy(final double sy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(1, 1, sy);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets z scaling factor.
     *
     * @return z scaling factor.
     */
    public double getSz() {
        return crossCouplingErrors.getElementAt(2, 2);
    }

    /**
     * Sets z scaling factor.
     *
     * @param sz z scaling factor.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non-invertible.
     */
    public void setSz(final double sz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(2, 2, sz);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets x-y cross coupling error.
     *
     * @return x-y cross coupling error.
     */
    public double getMxy() {
        return crossCouplingErrors.getElementAt(0, 1);
    }

    /**
     * Sets x-y cross coupling error.
     *
     * @param mxy x-y cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non-invertible.
     */
    public void setMxy(final double mxy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 1, mxy);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets x-z cross coupling error.
     *
     * @return x-z cross coupling error.
     */
    public double getMxz() {
        return crossCouplingErrors.getElementAt(0, 2);
    }

    /**
     * Sets x-z cross coupling error.
     *
     * @param mxz x-z cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non-invertible.
     */
    public void setMxz(final double mxz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 2, mxz);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets y-x cross coupling error.
     *
     * @return y-x cross coupling error.
     */
    public double getMyx() {
        return crossCouplingErrors.getElementAt(1, 0);
    }

    /**
     * Sets y-x cross coupling error.
     *
     * @param myx y-x cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non-invertible.
     */
    public void setMyx(final double myx) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(1, 0, myx);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets y-z cross coupling error.
     *
     * @return y-z cross coupling error.
     */
    public double getMyz() {
        return crossCouplingErrors.getElementAt(1, 2);
    }

    /**
     * Sets y-z cross coupling error.
     *
     * @param myz y-z cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non-invertible.
     */
    public void setMyz(final double myz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(1, 2, myz);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets z-x cross coupling error.
     *
     * @return z-x cross coupling error.
     */
    public double getMzx() {
        return crossCouplingErrors.getElementAt(2, 0);
    }

    /**
     * Sets z-x cross coupling error.
     *
     * @param mzx z-x cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non-invertible.
     */
    public void setMzx(final double mzx) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(2, 0, mzx);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets z-y cross coupling error.
     *
     * @return z-y cross coupling error.
     */
    public double getMzy() {
        return crossCouplingErrors.getElementAt(2, 1);
    }

    /**
     * Sets z-y cross coupling error.
     *
     * @param mzy z-y cross coupling error.
     * @throws AlgebraException if provided value makes cross coupling matrix
     *                          non-invertible.
     */
    public void setMzy(final double mzy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(2, 1, mzy);
        setCrossCouplingErrors(m);
    }

    /**
     * Sets scaling factors.
     *
     * @param sx x scaling factor.
     * @param sy y scaling factor.
     * @param sz z scaling factor.
     * @throws AlgebraException if provided values make cross coupling matrix
     *                          non-invertible.
     */
    public void setScalingFactors(
            final double sx, final double sy, final double sz) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 0, sx);
        m.setElementAt(1, 1, sy);
        m.setElementAt(2, 2, sz);
        setCrossCouplingErrors(m);
    }

    /**
     * Sets cross coupling errors.
     *
     * @param mxy x-y cross coupling error.
     * @param mxz x-z cross coupling error.
     * @param myx y-x cross coupling error.
     * @param myz y-z cross coupling error.
     * @param mzx z-x cross coupling error.
     * @param mzy z-y cross coupling error.
     * @throws AlgebraException if provided values make cross coupling matrix
     *                          non-invertible.
     */
    public void setCrossCouplingErrors(
            final double mxy, final double mxz, final double myx,
            final double myz, final double mzx, final double mzy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 1, mxy);
        m.setElementAt(0, 2, mxz);
        m.setElementAt(1, 0, myx);
        m.setElementAt(1, 2, myz);
        m.setElementAt(2, 0, mzx);
        m.setElementAt(2, 1, mzy);
        setCrossCouplingErrors(m);
    }

    /**
     * Sets scaling factors and cross coupling errors.
     *
     * @param sx  x scaling factor.
     * @param sy  y scaling factor.
     * @param sz  z scaling factor.
     * @param mxy x-y cross coupling error.
     * @param mxz x-z cross coupling error.
     * @param myx y-x cross coupling error.
     * @param myz y-z cross coupling error.
     * @param mzx z-x cross coupling error.
     * @param mzy z-y cross coupling error.
     * @throws AlgebraException if provided values make cross coupling matrix
     *                          non-invertible.
     */
    public void setScalingFactorsAndCrossCouplingErrors(
            final double sx, final double sy, final double sz,
            final double mxy, final double mxz, final double myx,
            final double myz, final double mzx, final double mzy) throws AlgebraException {
        final var m = new Matrix(Triad.COMPONENTS, Triad.COMPONENTS);
        m.copyFrom(crossCouplingErrors);
        m.setElementAt(0, 0, sx);
        m.setElementAt(1, 1, sy);
        m.setElementAt(2, 2, sz);
        m.setElementAt(0, 1, mxy);
        m.setElementAt(0, 2, mxz);
        m.setElementAt(1, 0, myx);
        m.setElementAt(1, 2, myz);
        m.setElementAt(2, 0, mzx);
        m.setElementAt(2, 1, mzy);
        setCrossCouplingErrors(m);
    }

    /**
     * Gets g-dependant cross biases matrix.
     *
     * @return g-dependant cross biases matrix.
     */
    public Matrix getGDependantCrossBias() {

final var result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @return initial gyroscope bias to be used to find a solution as a
     * column matrix.
     */
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * a column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial gyroscope bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @return initial bias coordinates.
     */
    public AngularSpeedTriad getInitialBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    public void getInitialBiasAsTriad(AngularSpeedTriad result) {
        result.setValueCoordinatesAndUnit(initialBiasX, initialBiasY, initialBiasZ,
                AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param initialBias initial bias coordinates to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setInitialBias(AngularSpeedTriad initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialBiasX = convertAngularSpeed(initialBias.getValueX(), initialBias.getUnit());
        initialBiasY = convertAngularSpeed(initialBias.getValueY(), initialBias.getUnit());
        initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @return collection of sequences of timestamped body kinematics
     * measurements.
     */
    @Override
    public List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> getSequences() {
        return sequences;
    }

    /**
     * Sets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @param sequences collection of sequences of timestamped body
     *                  kinematics measurements.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setSequences(
            final List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> sequences) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.sequences = sequences;
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.BODY_KINEMATICS_SEQUENCE;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return true;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement/sequence or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {

setResult(m, b, g);

        // at this point covariance is expressed in terms of b, M and G, and must
        // be expressed in terms of bg, Mg and Gg.
        // We know that:
        // bg = M * b
        // Mg = M - I
        // Gg = M * G

        // b = [bx]
        //     [by]
        //     [bz]

        // M = [m11  m12  m13]
        //     [m21  m22  m23]
        //     [m31  m32  m33]

        // G = [g11  g12  g13]
        //     [g21  g22  g23]
        //     [g31  g32  g33]

        // bg = [m11  m12  m13][bx] = [m11 * bx + m12 * by + m13 * bz] = [bgx]
        //      [m21  m22  m23][by]   [m21 * bx + m22 * by + m23 * bz]   [bgy]
        //      [m31  m32  m33][bz]   [m31 * bx + m32 * by + m33 * bz]   [bgz]

        // Mg = [sx  mxy  mxz] = [m11 - 1    m12         m13     ]
        //      [myx	sy	 myz]   [m21        m22 - 1     m23     ]
        //      [mzx	mzy  sz ]   [m31        m32         m33 - 1 ]

        // Gg = [gg11  gg12  gg13] = [m11  m12  m13][g11  g12  g13]
        //      [gg21  gg22  gg23]   [m21  m22  m23][g21  g22  g23]
        //      [gg31  gg32  gg33]   [m31  m32  m33][g31  g32  g33]

        // Defining the linear application:
        // F(b, M, G) = F(bx, by, bz, m11, m21, m31, m12, m22, m32, m13, m23, m33, g11, g21, g31, g12, g22, g32, g13, g23, g33)
        // as:
        // [bgx] =  [m11 * bx + m12 * by + m13 * bz]
        // [bgy]    [m21 * bx + m22 * by + m23 * bz]
        // [bgz]    [m31 * bx + m32 * by + m33 * bz]
        // [sx]     [m11 - 1]
        // [sy]     [m22 - 1]
        // [sz]     [m33 - 1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [m21]
        // [myz]    [m23]
        // [mzx]    [m31]
        // [mzy]    [m32]
        // [gg11]   [m11 * g11 + m12 * g21 + m13 * g31]
        // [gg21]   [m21 * g11 + m22 * g21 + m23 * g31]
        // [gg31]   [m31 * g11 + m32 * g21 + m33 * g31]
        // [gg12]   [m11 * g12 + m12 * g22 + m13 * g32]
        // [gg22]   [m21 * g12 + m22 * g22 + m23 * g32]
        // [gg32]   [m31 * g12 + m32 * g22 + m33 * g32]
        // [gg13]   [m11 * g13 + m12 * g23 + m13 * g33]
        // [gg23]   [m21 * g13 + m22 * g23 + m23 * g33]
        // [gg33]   [m31 * g13 + m32 * g23 + m33 * g33]

        // Then the Jacobian of F(b, M, G) is:
        // J = [m11  m12  m13  bx   0    0    by   0    0    bz   0    0    0    0    0    0    0    0    0    0    0  ]
        //     [m21  m22  m23  0    bx   0    0    by   0    0    bz   0    0    0    0    0    0    0    0    0    0  ]
        //     [m31  m32  m33  0    0    bx   0    0    by   0    0    bz   0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    g11  0    0    g21  0    0    g31  0    0    m11  m12  m13  0    0    0    0    0    0  ]
        //     [0    0    0    0    g11  0    0    g21  0    0    g31  0    m21  m22  m23  0    0    0    0    0    0  ]
        //     [0    0    0    0    0    g11  0    0    g21  0    0    g31  m31  m32  m33  0    0    0    0    0    0  ]
        //     [0    0    0    g12  0    0    g22  0    0    g32  0    0    0    0    0    m11  m12  m13  0    0    0  ]
        //     [0    0    0    0    g12  0    0    g22  0    0    g32  0    0    0    0    m21  m22  m23  0    0    0  ]
        //     [0    0    0    0    0    g12  0    0    g22  0    0    g32  0    0    0    m31  m32  m33  0    0    0  ]
        //     [0    0    0    g13  0    0    g23  0    0    g33  0    0    0    0    0    0    0    0    m11  m12  m13]
        //     [0    0    0    0    g13  0    0    g23  0    0    g33  0    0    0    0    0    0    0    m21  m22  m23]
        //     [0    0    0    0    0    g13  0    0    g23  0    0    g33  0    0    0    0    0    0    m31  m32  m33]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS_AND_CROSS_BIASES, GENERAL_UNKNOWNS_AND_CROSS_BIASES);

        jacobian.setElementAt(0, 0, m11);
        jacobian.setElementAt(0, 1, m12);
        jacobian.setElementAt(0, 2, m13);
        jacobian.setElementAt(0, 3, bx);
        jacobian.setElementAt(0, 6, by);
        jacobian.setElementAt(0, 9, bz);

        jacobian.setElementAt(1, 0, m21);
        jacobian.setElementAt(1, 1, m22);
        jacobian.setElementAt(1, 2, m23);
        jacobian.setElementAt(1, 4, bx);
        jacobian.setElementAt(1, 7, by);
        jacobian.setElementAt(1, 10, bz);

        jacobian.setElementAt(2, 0, m31);
        jacobian.setElementAt(2, 1, m32);
        jacobian.setElementAt(2, 2, m33);
        jacobian.setElementAt(2, 5, bx);
        jacobian.setElementAt(2, 8, by);
        jacobian.setElementAt(2, 11, bz);

        jacobian.setElementAt(3, 3, 1.0);
        jacobian.setElementAt(4, 7, 1.0);
        jacobian.setElementAt(5, 11, 1.0);

        jacobian.setElementAt(6, 6, 1.0);
        jacobian.setElementAt(7, 9, 1.0);
        jacobian.setElementAt(8, 4, 1.0);

        jacobian.setElementAt(9, 10, 1.0);
        jacobian.setElementAt(10, 5, 1.0);
        jacobian.setElementAt(11, 8, 1.9);

        jacobian.setElementAt(12, 3, g11);
        jacobian.setElementAt(12, 6, g21);
        jacobian.setElementAt(12, 9, g31);
        jacobian.setElementAt(12, 12, m11);
        jacobian.setElementAt(12, 13, m12);
        jacobian.setElementAt(12, 14, m13);

        jacobian.setElementAt(13, 4, g11);
        jacobian.setElementAt(13, 7, g21);
        jacobian.setElementAt(13, 10, g31);
        jacobian.setElementAt(13, 12, m21);
        jacobian.setElementAt(13, 13, m22);
        jacobian.setElementAt(13, 14, m23);

        jacobian.setElementAt(14, 5, g11);
        jacobian.setElementAt(14, 8, g21);
        jacobian.setElementAt(14, 11, g31);
        jacobian.setElementAt(14, 12, m31);
        jacobian.setElementAt(14, 13, m32);
        jacobian.setElementAt(14, 14, m33);

        jacobian.setElementAt(15, 3, g12);
        jacobian.setElementAt(15, 6, g22);
        jacobian.setElementAt(15, 9, g32);
        jacobian.setElementAt(15, 15, m11);
        jacobian.setElementAt(15, 16, m12);
        jacobian.setElementAt(15, 17, m13);

        jacobian.setElementAt(16, 4, g12);
        jacobian.setElementAt(16, 7, g22);
        jacobian.setElementAt(16, 10, g32);
        jacobian.setElementAt(16, 15, m21);
        jacobian.setElementAt(16, 16, m22);
        jacobian.setElementAt(16, 17, m23);

        jacobian.setElementAt(17, 5, g12);
        jacobian.setElementAt(17, 8, g22);
        jacobian.setElementAt(17, 11, g32);
        jacobian.setElementAt(17, 15, m31);
        jacobian.setElementAt(17, 16, m32);
        jacobian.setElementAt(17, 17, m33);

        jacobian.setElementAt(18, 3, g13);
        jacobian.setElementAt(18, 6, g23);
        jacobian.setElementAt(18, 9, g33);
        jacobian.setElementAt(18, 18, m11);
        jacobian.setElementAt(18, 19, m12);
        jacobian.setElementAt(18, 20, m13);

        jacobian.setElementAt(19, 4, g13);
        jacobian.setElementAt(19, 7, g23);
        jacobian.setElementAt(19, 10, g33);
        jacobian.setElementAt(19, 18, m21);
        jacobian.setElementAt(19, 19, m22);
        jacobian.setElementAt(19, 20, m23);

        jacobian.setElementAt(20, 5, g13);
        jacobian.setElementAt(20, 8, g23);
        jacobian.setElementAt(20, 11, g33);
        jacobian.setElementAt(20, 18, m31);
        jacobian.setElementAt(20, 19, m32);
        jacobian.setElementAt(20, 20, m33);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed
     * for both the accelerometer and gyroscope and G-dependent cross biases
     * are ignored.
     *
     * @throws AlgebraException                         if accelerometer parameters prevent fixing
     *                                                  measured accelerometer values due to numerical instabilities.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateCommonAxis() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {

jacobian.setElementAt(8, 5, 1.9);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Sets input data into Levenberg-Marquardt fitter when G-dependent cross biases
     * are taken into account.
     *
     * @throws AlgebraException                              if provided accelerometer cross coupling
     *                                                       errors are not valid.
     * @throws InvalidSourceAndDestinationFrameTypeException never happens
     */
    private void setInputDataWithGDependentCrossBiases()
            throws AlgebraException, InvalidSourceAndDestinationFrameTypeException {
        // compute reference frame at current position
        final var nedPosition = getNedPosition();
        final var nedC = new CoordinateTransformation(FrameType.BODY_FRAME, FrameType.LOCAL_NAVIGATION_FRAME);
        final var nedFrame = new NEDFrame(nedPosition, nedC);
        final var ecefFrame = NEDtoECEFFrameConverter.convertNEDtoECEFAndReturnNew(nedFrame);
        final var refKinematics = ECEFKinematicsEstimator.estimateKinematicsAndReturnNew(timeInterval, ecefFrame,
                ecefFrame);

        final var refAngularRateX = refKinematics.getAngularRateX();
        final var refAngularRateY = refKinematics.getAngularRateY();
        final var refAngularRateZ = refKinematics.getAngularRateZ();

        final var w2 = turntableRotationRate * turntableRotationRate;

        final var numMeasurements = measurements.size();
        final var x = new Matrix(numMeasurements, 2 * BodyKinematics.COMPONENTS);
        final var y = new double[numMeasurements];
        final var angularRateStandardDeviations = new double[numMeasurements];
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredKinematics = measurement.getKinematics();

            final var angularRateX = measuredKinematics.getAngularRateX();
            final var angularRateY = measuredKinematics.getAngularRateY();
            final var angularRateZ = measuredKinematics.getAngularRateZ();

            final var fX = measuredKinematics.getFx();
            final var fY = measuredKinematics.getFy();
            final var fZ = measuredKinematics.getFz();

            x.setElementAt(i, 0, angularRateX - refAngularRateX);
            x.setElementAt(i, 1, angularRateY - refAngularRateY);
            x.setElementAt(i, 2, angularRateZ - refAngularRateZ);

            x.setElementAt(i, 3, fX);
            x.setElementAt(i, 4, fY);
            x.setElementAt(i, 5, fZ);

            y[i] = w2;

            angularRateStandardDeviations[i] = measurement.getAngularRateStandardDeviation();

            i++;
        }

        fitter.setInputData(x, y, angularRateStandardDeviations);

        ba = getAccelerometerBiasAsMatrix();
        ma = getAccelerometerMa();
        accelerationFixer.setBias(ba);
        accelerationFixer.setCrossCouplingErrors(ma);
    }

    /**
     * Sets input data into Levenberg-Marquardt fitter when G-dependent cross biases
     * are ignored.
     *
     * @throws AlgebraException                              if provided accelerometer cross coupling
     *                                                       errors are not valid.
     * @throws InvalidSourceAndDestinationFrameTypeException never happens.
     */
    private void setInputData() throws AlgebraException, InvalidSourceAndDestinationFrameTypeException {

        // compute reference frame at current position
        final var nedPosition = getNedPosition();
        final var nedC = new CoordinateTransformation(FrameType.BODY_FRAME, FrameType.LOCAL_NAVIGATION_FRAME);
        final var nedFrame = new NEDFrame(nedPosition, nedC);
        final var ecefFrame = NEDtoECEFFrameConverter.convertNEDtoECEFAndReturnNew(nedFrame);
        final var refKinematics = ECEFKinematicsEstimator.estimateKinematicsAndReturnNew(timeInterval, ecefFrame,
                ecefFrame);

        final var refAngularRateX = refKinematics.getAngularRateX();
        final var refAngularRateY = refKinematics.getAngularRateY();
        final var refAngularRateZ = refKinematics.getAngularRateZ();

        final var w2 = turntableRotationRate * turntableRotationRate;

        final var numMeasurements = measurements.size();
        final var x = new Matrix(numMeasurements, BodyKinematics.COMPONENTS);
        final var y = new double[numMeasurements];
        final var angularRateStandardDeviations = new double[numMeasurements];
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredKinematics = measurement.getKinematics();

            final var angularRateX = measuredKinematics.getAngularRateX();
            final var angularRateY = measuredKinematics.getAngularRateY();
            final var angularRateZ = measuredKinematics.getAngularRateZ();

            x.setElementAt(i, 0, angularRateX - refAngularRateX);
            x.setElementAt(i, 1, angularRateY - refAngularRateY);
            x.setElementAt(i, 2, angularRateZ - refAngularRateZ);

            y[i] = w2;

            angularRateStandardDeviations[i] = measurement.getAngularRateStandardDeviation();

            i++;
        }

        fitter.setInputData(x, y, angularRateStandardDeviations);

        ba = getAccelerometerBiasAsMatrix();
        ma = getAccelerometerMa();
        accelerationFixer.setBias(ba);
        accelerationFixer.setCrossCouplingErrors(ma);
    }

    /**
     * Converts provided NED position expressed in terms of latitude, longitude and height respect
     * mean Earth surface, to position expressed in ECEF coordinates.
     *
     * @param position NED position to be converted.
     * @return converted position expressed in ECEF coordinates.
     */
    private static ECEFPosition convertPosition(final NEDPosition position) {
        final var velocity = new ECEFVelocity();
        final var result = new ECEFPosition();
        NEDtoECEFPositionVelocityConverter.convertNEDtoECEF(
                position.getLatitude(), position.getLongitude(), position.getHeight(), 0.0, 0.0, 0.0,
                result, velocity);
        return result;
    }

    /**
     * Converts acceleration instance to meters per squared second.
     *
     * @param acceleration acceleration instance to be converted.
     * @return converted value.
     */
    private static double convertAcceleration(final Acceleration acceleration) {
        return AccelerationConverter.convert(acceleration.getValue().doubleValue(), acceleration.getUnit(),
                AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Converts angular speed instance to radians per second (rad/s).
     *
     * @param value angular speed value.
     * @param unit  unit of angular speed value.
     * @return converted value.
     */
    private static double convertAngularSpeed(final double value, final AngularSpeedUnit unit) {
        return AngularSpeedConverter.convert(value, unit, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Converts angular speed instance to radians per second (rad/s).
     *
     * @param angularSpeed angular speed instance to be converted.
     * @return converted value.
     */
    private static double convertAngularSpeed(final AngularSpeed angularSpeed) {
        return convertAngularSpeed(angularSpeed.getValue().doubleValue(), angularSpeed.getUnit());
    }

    /**
     * Converts time instance to seconds.
     *
     * @param time time instance to be converted.
     * @return converted value.
     */
    private static double convertTime(final Time time) {
        return TimeConverter.convert(time.getValue().doubleValue(), time.getUnit(), TimeUnit.SECOND);
    }

    /**
     * Makes proper conversion of internal cross-coupling and g-dependent
     * cross bias matrices.
     *
     * @param m internal scaling and cross-coupling matrix.
     * @param g internal g-dependent cross bias matrix.
     * @throws AlgebraException if a numerical instability occurs.
     */
    private void setResult(final Matrix m, final Matrix g) throws AlgebraException {

biasZ = convertAcceleration(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param bias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        internalSetBias(bias);
    }

    /**
     * Gets known accelerometer bias as a column matrix.
     *
     * @return known accelerometer bias as a column matrix.
     */
    @Override
    public Matrix getBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, biasX);
        result.setElementAtIndex(1, biasY);
        result.setElementAtIndex(2, biasZ);
    }

    /**
     * Sets known accelerometer bias as a column matrix.
     *
     * @param bias accelerometer bias to be set.
     * @throws LockedException          if calibrator is currently running
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setBias(final Matrix bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        internalSetBias(bias);
    }

    /**
     * Gets initial x scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {

}
    }

    /**
     * Gets estimated average of x coordinate of measurement expressed in its default
     * unit (m/s^2 for acceleration, rad/s for angular speed or T for magnetic flux density).
     * This value will depend of body location and orientation, hence it should never
     * be used as a calibration bias.
     *
     * @return average of x coordinate of measurement in current window.
     */
    public double getAvgX() {
        return avgX;
    }

    /**
     * Gets estimated average of x coordinate of measurement within current window.
     * This value will depend of body location and orientation, hence it should never
     * be used as a calibration bias.
     *
     * @return average of x coordinate of measurement in current window.
     */
    public M getAvgXAsMeasurement() {
        return createMeasurement(avgX, getDefaultUnit());
    }

    /**
     * Gets estimated average of x coordinate of measurement within current window.
     * This value will depend of body location and orientation, hence it should never
     * be used as a calibration bias.
     *
     * @param result instance where average of x coordinate of measurement will be stored.
     */
    public void getAvgXAsMeasurement(final M result) {
        result.setValue(avgX);
        result.setUnit(getDefaultUnit());
    }

    /**
     * Gets estimated average of y coordinate of measurement expressed in its default
     * unit (m/s^2 for acceleration, rad/s for angular speed or T for magnetic flux density).
     * This value will depend of body location and orientation, hence it should never
     * be used as a calibration bias.
     *
     * @return average of y coordinate of measurement in current window.
     */
    public double getAvgY() {
        return avgY;
    }

    /**
     * Gets estimated average of y coordinate of measurement within current window.
     * This value will depend of body location and orientation, hence it should never
     * be used as a calibration bias.
     *
     * @return average of y coordinate of measurement in current window.
     */
    public M getAvgYAsMeasurement() {
        return createMeasurement(avgY, getDefaultUnit());
    }

    /**
     * Gets estimated average of y coordinate of measurement within current window.
     * This value will depend of body location and orientation, hence it should never
     * be used as a calibration bias.
     *
     * @param result instance where average of y coordinate of measurement will be stored.
     */
    public void getAvgYAsMeasurement(final M result) {
        result.setValue(avgY);
        result.setUnit(getDefaultUnit());
    }

    /**
     * Gets estimated average of z coordinate of measurement expressed in its default
     * unit (m/s^2 for acceleration, rad/s for angular speed or T for magnetic flux density).
     * This value will depend of body location and orientation, hence it should never
     * be used as a calibration bias.
     *
     * @return average of z coordinate of measurement in current window.
     */
    public double getAvgZ() {
        return avgZ;
    }

    /**
     * Gets estimated average of z coordinate of measurement within current window.
     * This value will depend of body location and orientation, hence it should never
     * be used as a calibration bias.
     *
     * @return average of z coordinate of measurement in current window.
     */
    public M getAvgZAsMeasurement() {
        return createMeasurement(avgZ, getDefaultUnit());
    }

    /**
     * Gets estimated average of z coordinate of measurement within current window.
     * This value will depend of body location and orientation, hence it should never
     * be used as a calibration bias.
     *
     * @param result instance where average of z coordinate of measurement will be stored.
     */
    public void getAvgZAsMeasurement(final M result) {
        result.setValue(avgZ);
        result.setUnit(getDefaultUnit());
    }

    /**
     * Gets estimated average as a measurement triad.
     *
     * @return average measurement triad.
     */
    public T getAvgTriad() {
        return createTriad(avgX, avgY, avgZ, getDefaultUnit());
    }

    /**
     * Gets estimated average as a measurement triad.
     *
     * @param result instance where average values and unit will be stored.
     */
    public void getAvgTriad(final T result) {
        result.setValueCoordinatesAndUnit(avgX, avgY, avgZ, getDefaultUnit());
    }

    /**
     * Gets norm of estimated average measurement expressed in its default
     * unit (m/s^2 for acceleration, rad/s for angular speed or T for magnetic flux density).
     * This value is independent of body orientation.
     *
     * @return norm of estimated average specific force.
     */
    public double getAvgNorm() {
        return Math.sqrt(avgX * avgX + avgY * avgY + avgZ * avgZ);
    }

    /**
     * Gets norm of estimated average measurement within current window.
     *
     * @return norm of estimated average measurement.
     */
    public M getAvgNormAsMeasurement() {
        return createMeasurement(getAvgNorm(), getDefaultUnit());
    }

    /**
     * Gets norm of estimated average measurement within current window.
     *
     * @param result instance where norm of estimated average measurement will be stored.
     */
    public void getAvgNormAsMeasurement(final M result) {
        result.setValue(getAvgNorm());
        result.setUnit(getDefaultUnit());
    }

    /**
     * Gets estimated variance of x coordinate of measurement within current window
     * expressed in its default squared unit (m^2/s^4 for acceleration,
     * rad^2/s^2 for angular speed or T^2 for magnetic flux density).
     *
     * @return estimated variance of x coordinate of measurement within current
     * window.
     */
    public double getVarianceX() {
        return varianceX;
    }

    /**
     * Gets estimated variance of y coordinate of measurement within current window
     * expressed in its default squared unit (m^2/s^4 for acceleration,
     * rad^2/s^2 for angular speed or T^2 for magnetic flux density).
     *
     * @return estimated variance of y coordinate of measurement within current
     * window.
     */
    public double getVarianceY() {
        return varianceY;
    }

    /**
     * Gets estimated variance of z coordinate of measurement within current window
     * expressed in its default squared unit (m^2/s^4 for acceleration,
     * rad^2/s^2 for angular speed or T^2 for magnetic flux density).
     *
     * @return estimated variance of z coordinate of measurement within current
     * window.
     */
    public double getVarianceZ() {
        return varianceZ;
    }

    /**
     * Gets estimated standard deviation of x coordinate of measurement within current
     * window and expressed in its default unit (m/s^2 for acceleration, rad/s for
     * angular speed or T for magnetic flux density).
     *
     * @return estimated standard deviation of x coordinate of measurement within
     * current window.
     */
    public double getStandardDeviationX() {
        return Math.sqrt(varianceX);
    }

    /**
     * Gets estimated standard deviation of x coordinate of measurement within current
     * window.
     *
     * @return estimated standard deviation of x coordinate of measurement.
     */
    public M getStandardDeviationXAsMeasurement() {
        return createMeasurement(getStandardDeviationX(), getDefaultUnit());
    }

    /**
     * Gets estimated standard deviation of x coordinate of measurement within current
     * window.
     *
     * @param result instance where estimated standard deviation of x coordinate of
     *               measurement will be stored.
     */
    public void getStandardDeviationXAsMeasurement(final M result) {
        result.setValue(getStandardDeviationX());
        result.setUnit(getDefaultUnit());
    }

    /**
     * Gets estimated standard deviation of y coordinate of measurement within current
     * window and expressed in its default unit (m/s^2 for acceleration, rad/s for
     * angular speed or T for magnetic flux density).
     *
     * @return estimated standard deviation of y coordinate of measurement within
     * current window.
     */
    public double getStandardDeviationY() {
        return Math.sqrt(varianceY);
    }

    /**
     * Gets estimated standard deviation of y coordinate of measurement within current
     * window.
     *
     * @return estimated standard deviation of y coordinate of measurement.
     */
    public M getStandardDeviationYAsMeasurement() {
        return createMeasurement(getStandardDeviationY(), getDefaultUnit());
    }

    /**
     * Gets estimated standard deviation of y coordinate of measurement within current
     * window.
     *
     * @param result instance where estimated standard deviation of y coordinate of
     *               measurement will be stored.
     */
    public void getStandardDeviationYAsMeasurement(final M result) {
        result.setValue(getStandardDeviationY());
        result.setUnit(getDefaultUnit());
    }

    /**
     * Gets estimated standard deviation of z coordinate of measurement within current
     * window and expressed in its default unit (m/s^2 for acceleration, rad/s for
     * angular speed or T for magnetic flux density).
     *
     * @return estimated standard deviation of z coordinate of measurement within
     * current window.
     */
    public double getStandardDeviationZ() {
        return Math.sqrt(varianceZ);
    }

    /**
     * Gets estimated standard deviation of z coordinate of measurement within current
     * window.
     *
     * @return estimated standard deviation of z coordinate of measurement.
     */
    public M getStandardDeviationZAsMeasurement() {
        return createMeasurement(getStandardDeviationZ(), getDefaultUnit());
    }

    /**
     * Gets estimated standard deviation of z coordinate of measurement within current
     * window.
     *
     * @param result instance where estimated standard deviation of z coordinate of
     *               measurement will be stored.
     */
    public void getStandardDeviationZAsMeasurement(final M result) {
        result.setValue(getStandardDeviationZ());
        result.setUnit(getDefaultUnit());
    }

    /**
     * Gets estimated standard deviation of measurements.
     *
     * @return estimated standard deviation triad of measurements.
     */
    public T getStandardDeviationTriad() {
        return createTriad(getStandardDeviationX(), getStandardDeviationY(), getStandardDeviationZ(), getDefaultUnit());
    }

    /**
     * Gets estimated standard deviation of measurement within current window.
     *
     * @param result instance where estimated standard deviation triad of
     *               measurement will be stored.
     */
    public void getStandardDeviationTriad(final T result) {
        result.setValueCoordinatesAndUnit(getStandardDeviationX(), getStandardDeviationY(), getStandardDeviationZ(),
                getDefaultUnit());
    }

    /**
     * Gets norm of estimated standard deviation of measurement
     * expressed in its default unit (m/s^2 for acceleration, rad/s for
     * angular speed or T for magnetic flux density).
     *
     * @return norm of estimated standard deviation of measurement.
     */
    public double getStandardDeviationNorm() {
        final var fx = getStandardDeviationX();
        final var fy = getStandardDeviationY();
        final var fz = getStandardDeviationZ();
        return Math.sqrt(fx * fx + fy * fy + fz * fz);
    }

    /**
     * Gets norm of estimated standard deviation of measurements.
     *
     * @return norm of estimated standard deviation of measurement.
     */
    public M getStandardDeviationNormAsMeasurement() {
        return createMeasurement(getStandardDeviationNorm(), getDefaultUnit());
    }

    /**
     * Gets norm of estimated standard deviation of measurement within current window.
     *
     * @param result instance where norm of estimated standard deviation will be stored.
     */
    public void getStandardDeviationNormAsMeasurement(final M result) {
        result.setValue(getStandardDeviationNorm());
        result.setUnit(getDefaultUnit());
    }

    /**
     * Gets average of estimated standard deviation coordinates of measurement
     * expressed in its default unit (m/s^2 for acceleration, rad/s for
     * angular speed or T for magnetic flux density).
     *
     * @return average of estimated standard deviation coordinates.
     */
    public double getAverageStandardDeviation() {
        final var fx = getStandardDeviationX();
        final var fy = getStandardDeviationY();
        final var fz = getStandardDeviationZ();
        return (fx + fy + fz) / 3.0;
    }

    /**
     * Gets average of estimated standard deviation coordinates of measurement within
     * current window.
     *
     * @return average of estimated standard deviation coordinates.
     */
    public M getAverageStandardDeviationAsMeasurement() {
        return createMeasurement(getAverageStandardDeviation(), getDefaultUnit());
    }

    /**
     * Gets average of estimated standard deviation coordinates of measurement.
     *
     * @param result instance where average of estimated standard deviation coordinates
     *               will be stored.
     */
    public void getAverageStandardDeviationAsMeasurement(final M result) {
        result.setValue(getAverageStandardDeviation());
        result.setUnit(getDefaultUnit());
    }

    /**
     * Gets measurement noise PSD (Power Spectral Density) on x axis expressed
     * in (m^2 * s^-3) for accelerometer, (rad^2/s) for gyroscope or (T^2 * s) for
     * magnetometer.
     *
     * @return measurement noise PSD on x axis.
     */
    public double getPsdX() {
        return varianceX * timeInterval;
    }

    /**
     * Gets measurement noise PSD (Power Spectral Density) on y axis expressed
     * in (m^2 * s^-3) for accelerometer, (rad^2/s) for gyroscope or (T^2 * s) for
     * magnetometer.
     *
     * @return measurement noise PSD on y axis.
     */
    public double getPsdY() {
        return varianceY * timeInterval;
    }

    /**
     * Gets measurement noise PSD (Power Spectral Density) on z axis expressed
     * in (m^2 * s^-3) for accelerometer, (rad^2/s) for gyroscope or (T^2 * s) for
     * magnetometer.
     *
     * @return measurement noise PSD on z axis.
     */
    public double getPsdZ() {
        return varianceZ * timeInterval;
    }

    /**
     * Gets measurement noise root PSD (Power Spectral Density) on x axis expressed in
     * (m * s^-1.5) for accelerometer, (rad * s^-0.5) for gyroscope or (T * s^0.5) for
     * magnetometer.
     *
     * @return measurement noise root PSD on x axis.
     */
    public double getRootPsdX() {
        return Math.sqrt(getPsdX());
    }

    /**
     * Gets measurement noise root PSD (Power Spectral Density) on y axis expressed in
     * (m * s^-1.5) for accelerometer, (rad * s^-0.5) for gyroscope or (T * s^0.5) for
     * magnetometer.
     *
     * @return measurement noise root PSD on y axis.
     */
    public double getRootPsdY() {
        return Math.sqrt(getPsdY());
    }

    /**
     * Gets measurement noise root PSD (Power Spectral Density) on z axis expressed in
     * (m * s^-1.5) for accelerometer, (rad * s^-0.5) for gyroscope or (T * s^0.5) for
     * magnetometer.
     *
     * @return measurement noise root PSD on z axis.
     */
    public double getRootPsdZ() {
        return Math.sqrt(getPsdZ());
    }

    /**
     * Gets average measurement noise PSD (Power Spectral Density) among
     * x,y,z components expressed as (m^2 * s^-3) for accelerometer,
     * (rad^2/s) for gyroscope or (T^2 * s) for magnetometer.
     *
     * @return average measurement noise PSD.
     */
    public double getAvgNoisePsd() {
        return (getPsdX() + getPsdY() + getPsdZ()) / 3.0;
    }

    /**
     * Gets norm of noise root PSD (Power Spectral Density) among x,y,z
     * components expressed as (m * s^-1.5) for accelerometer,
     * (rad * s^-0.5) for gyroscope or (T * s^0.5) for magnetometer.
     *
     * @return norm of measurement noise root PSD.
     */
    public double getNoiseRootPsdNorm() {
        return Math.sqrt(getPsdX() + getPsdY() + getPsdZ());
    }

    /**
     * Gets number of samples that have been processed so far.
     *
     * @return number of samples that have been processed so far.
     */
    public int getNumberOfProcessedSamples() {
        return numberOfProcessedSamples;
    }

    /**
     * Indicates whether estimator is currently running or not.
     *
     * @return true if estimator is running, false otherwise.
     */
    public boolean isRunning() {

setInputData();

        fitter.fit();

        final var result = fitter.getA();

        final var m11 = result[0];

        final var m12 = result[1];
        final var m22 = result[2];

        final var m13 = result[3];
        final var m23 = result[4];
        final var m33 = result[5];

        final var g11 = result[6];
        final var g21 = result[7];
        final var g31 = result[8];

        final var g12 = result[9];
        final var g22 = result[10];
        final var g32 = result[11];

        final var g13 = result[12];
        final var g23 = result[13];
        final var g33 = result[14];

        final var mm = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        mm.setElementAtIndex(0, m11);
        mm.setElementAtIndex(1, 0.0);
        mm.setElementAtIndex(2, 0.0);

        mm.setElementAtIndex(3, m12);
        mm.setElementAtIndex(4, m22);
        mm.setElementAtIndex(5, 0.0);

        mm.setElementAtIndex(6, m13);
        mm.setElementAtIndex(7, m23);
        mm.setElementAtIndex(8, m33);

        final var mg = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        mg.setElementAtIndex(0, g11);
        mg.setElementAtIndex(1, g21);
        mg.setElementAtIndex(2, g31);

        mg.setElementAtIndex(3, g12);
        mg.setElementAtIndex(4, g22);
        mg.setElementAtIndex(5, g32);

        mg.setElementAtIndex(6, g13);
        mg.setElementAtIndex(7, g23);
        mg.setElementAtIndex(8, g33);

        setResult(mm, mg);

        // at this point covariance is expressed in terms of M and G, and must
        // be expressed in terms of Mg and Gg.
        // We know that:
        // Mg = M - I
        // Gg = M * G

        // M = [m11  m12  m13]
        //     [0    m22  m23]
        //     [0    0    m33]

        // G = [g11  g12  g13]
        //     [g21  g22  g23]
        //     [g31  g32  g33]

        // Mg = [sx  mxy  mxz] = [m11 - 1    m12         m13     ]
        //      [myx sy	  myz]   [0          m22 - 1     m23     ]
        //      [mzx mzy  sz ]   [0          0           m33 - 1 ]

        // Gg = [gg11  gg12  gg13] = [m11  m12  m13][g11  g12  g13]
        //      [gg21  gg22  gg23]   [0    m22  m23][g21  g22  g23]
        //      [gg31  gg32  gg33]   [0    0    m33][g31  g32  g33]

        // Defining the linear application:
        // F(M, G) = F(m11, m12, m22, m32=0, m13, m23, m33, g11, g21, g31, g12, g22, g32, g13, g23, g33)
        // as:
        // [sx] =   [m11 - 1]
        // [sy]     [m22 - 1]
        // [sz]     [m33 - 1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [0]
        // [myz]    [m23]
        // [mzx]    [0]
        // [mzy]    [0]
        // [gg11]   [m11 * g11 + m12 * g21 + m13 * g31]
        // [gg21]   [            m22 * g21 + m23 * g31]
        // [gg31]   [                        m33 * g31]
        // [gg12]   [m11 * g12 + m12 * g22 + m13 * g32]
        // [gg22]   [            m22 * g22 + n23 * g32]
        // [gg32]   [                        m33 * g32]
        // [gg13]   [m11 * g13 + m12 * g23 + m13 * g33]
        // [gg23]   [            m22 * g23 + m23 * g33]
        // [gg33]   [                        m33 * g33]

        // Then the Jacobian of F(M, G) is:
        // J = [1    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    1    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    1    0    0    0    0    0    0    0    0    0  ]
        //     [0    1    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    1    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    1    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [g11  g21  0    g31  0    0    m11  m12  m13  0    0    0    0    0    0  ]
        //     [0    0    g21  0    g31  0    0    m22  m23  0    0    0    0    0    0  ]
        //     [0    0    0    0    0    g31  0    0    m33  0    0    0    0    0    0  ]
        //     [g12  g22  0    g32  0    0    0    0    0    m11  m12  m13  0    0    0  ]
        //     [0    0    g22  0    g32  0    0    0    0    0    m22  m23  0    0    0  ]
        //     [0    0    0    0    0    g32  0    0    0    0    0    m33  0    0    0  ]
        //     [g13  g23  0    g33  0    0    0    0    0    0    0    0    m11  m12  m13]
        //     [0    0    g23  0    g33  0    0    0    0    0    0    0    0    m22  m23]
        //     [0    0    0    0    0    g33  0    0    0    0    0    0    0    0    m33]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS_AND_CROSS_BIASES, COMMON_Z_AXIS_UNKNOWNS_AND_CROSS_BIASES);

        jacobian.setElementAt(0, 0, 1.0);
        jacobian.setElementAt(1, 2, 1.0);
        jacobian.setElementAt(2, 5, 1.0);

        jacobian.setElementAt(3, 1, 1.0);
        jacobian.setElementAt(4, 3, 1.0);

        jacobian.setElementAt(6, 4, 1.0);

        jacobian.setElementAt(9, 0, g11);
        jacobian.setElementAt(9, 1, g21);
        jacobian.setElementAt(9, 3, g31);
        jacobian.setElementAt(9, 6, m11);
        jacobian.setElementAt(9, 7, m12);
        jacobian.setElementAt(9, 8, m13);

        jacobian.setElementAt(10, 2, g21);
        jacobian.setElementAt(10, 4, g31);
        jacobian.setElementAt(10, 7, m22);
        jacobian.setElementAt(10, 8, m23);

        jacobian.setElementAt(11, 5, g31);
        jacobian.setElementAt(11, 8, m33);

        jacobian.setElementAt(12, 0, g12);
        jacobian.setElementAt(12, 1, g22);
        jacobian.setElementAt(12, 3, g32);
        jacobian.setElementAt(12, 9, m11);
        jacobian.setElementAt(12, 10, m12);
        jacobian.setElementAt(12, 11, m13);

        jacobian.setElementAt(13, 2, g22);
        jacobian.setElementAt(13, 4, g32);
        jacobian.setElementAt(13, 10, m22);
        jacobian.setElementAt(13, 11, m23);

        jacobian.setElementAt(14, 5, g32);
        jacobian.setElementAt(14, 11, m33);

        jacobian.setElementAt(15, 0, g13);
        jacobian.setElementAt(15, 1, g23);
        jacobian.setElementAt(15, 3, g33);
        jacobian.setElementAt(15, 12, m11);
        jacobian.setElementAt(15, 13, m12);
        jacobian.setElementAt(15, 14, m13);

        jacobian.setElementAt(16, 2, g23);
        jacobian.setElementAt(16, 4, g33);
        jacobian.setElementAt(16, 13, m22);
        jacobian.setElementAt(16, 14, m23);

        jacobian.setElementAt(17, 5, g33);
        jacobian.setElementAt(17, 14, m33);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Internal method to perform general calibration when G-dependent cross
     * biases are being estimated.
     *
     * @throws AlgebraException                         if accelerometer parameters prevent fixing
     *                                                  measured accelerometer values due to numerical instabilities.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateGeneralAndGDependentCrossBiases() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {

} catch (final FittingException | AlgebraException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where estimated gyroscope biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return column matrix containing x,y,z components of estimated gyroscope
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasX() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasY() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasZ() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedX() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[0], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedX(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedY() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[1], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedY(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedZ() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedZ(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @return estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeedTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated gyroscope bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AngularSpeedTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

}

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where estimated gyroscope biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return column matrix containing x,y,z components of estimated gyroscope
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasX() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasY() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias expressed in radians per
     * second (rad/s).
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasZ() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedX() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[0], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedX(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedY() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[1], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedY(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedZ() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedZ(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @return estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeedTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated gyroscope bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AngularSpeedTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bgx, bgy, bgz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32,
     * gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

} catch (final AlgebraException | IOException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @return array containing x,y,z components of estimated magnetometer
     * hard-iron biases.
     */
    @Override
    public double[] getEstimatedHardIron() {
        return estimatedHardIron;
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where estimated magnetometer biases will be
     *               stored.
     * @return true if result instance was updated, false otherwise (when
     * estimation is not yet available).
     */
    @Override
    public boolean getEstimatedHardIron(final double[] result) {
        if (estimatedHardIron != null) {
            System.arraycopy(estimatedHardIron, 0, result, 0, estimatedHardIron.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @return column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases.
     */
    @Override
    public Matrix getEstimatedHardIronAsMatrix() {
        return estimatedHardIron != null ? Matrix.newFromArray(estimatedHardIron) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedHardIronAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedHardIron != null) {
            result.fromArray(estimatedHardIron);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return x coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronX() {
        return estimatedHardIron != null ? estimatedHardIron[0] : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return y coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronY() {
        return estimatedHardIron != null ? estimatedHardIron[1] : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return z coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronZ() {
        return estimatedHardIron != null ? estimatedHardIron[2] : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @return x coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronXAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[0], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[0]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @return y coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronYAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[1], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[1]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @return z coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronZAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[2], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[2]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @return estimated magnetometer bias or null if not available.
     */
    @Override
    public MagneticFluxDensityTriad getEstimatedHardIronAsTriad() {
        return estimatedHardIron != null
                ? new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2]) : null;
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronAsTriad(final MagneticFluxDensityTriad result) {
        if (estimatedHardIron != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2], MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

} catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @return array containing x,y,z components of estimated magnetometer
     * hard-iron biases.
     */
    @Override
    public double[] getEstimatedHardIron() {
        return estimatedHardIron;
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where estimated magnetometer biases will be
     *               stored.
     * @return true if result instance was updated, false otherwise (when
     * estimation is not yet available).
     */
    @Override
    public boolean getEstimatedHardIron(final double[] result) {
        if (estimatedHardIron != null) {
            System.arraycopy(estimatedHardIron, 0, result, 0, estimatedHardIron.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @return column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases.
     */
    @Override
    public Matrix getEstimatedHardIronAsMatrix() {
        return estimatedHardIron != null ? Matrix.newFromArray(estimatedHardIron) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedHardIronAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedHardIron != null) {
            result.fromArray(estimatedHardIron);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return x coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronX() {
        return estimatedHardIron != null ? estimatedHardIron[0] : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return y coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronY() {
        return estimatedHardIron != null ? estimatedHardIron[1] : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return z coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronZ() {
        return estimatedHardIron != null ? estimatedHardIron[2] : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @return x coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronXAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[0], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[0]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @return y coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronYAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[1], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[1]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @return z coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronZAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[2], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[2]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @return estimated magnetometer bias or null if not available.
     */
    @Override
    public MagneticFluxDensityTriad getEstimatedHardIronAsTriad() {
        return estimatedHardIron != null
                ? new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2])
                : null;
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronAsTriad(final MagneticFluxDensityTriad result) {
        if (estimatedHardIron != null) {
            result.setValueCoordinatesAndUnit(estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2],
                    MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

}

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where estimated gyroscope biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return column matrix containing x,y,z component of estimated gyroscope
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasX() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasY() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasZ() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @return x coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedX() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[0], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedX(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @return y coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedY() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[1], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedY(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @return z coordinate of estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeed getEstimatedBiasAngularSpeedZ() {
        return estimatedBiases != null
                ? new AngularSpeed(estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasAngularSpeedZ(final AngularSpeed result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @return estimated gyroscope bias or null if not available.
     */
    @Override
    public AngularSpeedTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated gyroscope bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AngularSpeedTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2], AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing g-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

}

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return array containing x,y,z components of estimated accelerometer biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where estimated accelerometer biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return column matrix containing x,y,z components of estimated accelerometer
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFx() {
        return estimatedBiases != null ? estimatedBiases[0] : null;
    }

    /**
     * Gets y coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return y coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFy() {
        return estimatedBiases != null ? estimatedBiases[1] : null;
    }

    /**
     * Gets z coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return z coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFz() {
        return estimatedBiases != null ? estimatedBiases[2] : null;
    }

    /**
     * Gets x coordinate of estimated accelerometer bias.
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Acceleration getEstimatedBiasFxAsAcceleration() {
        return estimatedBiases != null
                ? new Acceleration(estimatedBiases[0], AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets x coordinate of estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasFxAsAcceleration(final Acceleration result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[0]);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated accelerometer bias.
     *
     * @return y coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Acceleration getEstimatedBiasFyAsAcceleration() {
        return estimatedBiases != null
                ? new Acceleration(estimatedBiases[1], AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets y coordinate of estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasFyAsAcceleration(final Acceleration result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[1]);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated accelerometer bias.
     *
     * @return z coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Acceleration getEstimatedBiasFzAsAcceleration() {
        return estimatedBiases != null
                ? new Acceleration(estimatedBiases[2], AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets z coordinate of estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if result was updated, false if estimation is not available.
     */
    @Override
    public boolean getEstimatedBiasFzAsAcceleration(final Acceleration result) {
        if (estimatedBiases != null) {
            result.setValue(estimatedBiases[2]);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated accelerometer bias.
     *
     * @return estimated accelerometer bias or null if not available.
     */
    @Override
    public AccelerationTriad getEstimatedBiasAsTriad() {
        return estimatedBiases != null
                ? new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND,
                estimatedBiases[0], estimatedBiases[1], estimatedBiases[2])
                : null;
    }

    /**
     * Gets estimated accelerometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated accelerometer bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedBiasAsTriad(final AccelerationTriad result) {
        if (estimatedBiases != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedBiases[0], estimatedBiases[1], estimatedBiases[2],
                    AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated accelerometer scale factors and cross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {
        return estimatedMa;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 1) : null;
    }

}

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @return array containing x,y,z components of estimated magnetometer
     * hard-iron biases.
     */
    @Override
    public double[] getEstimatedHardIron() {
        return estimatedHardIron;
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where estimated magnetometer biases will be
     *               stored.
     * @return true if result instance was updated, false otherwise (when
     * estimation is not yet available).
     */
    @Override
    public boolean getEstimatedHardIron(final double[] result) {
        if (estimatedHardIron != null) {
            System.arraycopy(estimatedHardIron, 0, result, 0, estimatedHardIron.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @return column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases.
     */
    @Override
    public Matrix getEstimatedHardIronAsMatrix() {
        return estimatedHardIron != null ? Matrix.newFromArray(estimatedHardIron) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated
     * magnetometer hard-iron biases expressed in Teslas (T).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedHardIronAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedHardIron != null) {
            result.fromArray(estimatedHardIron);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return x coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronX() {
        return estimatedHardIron != null ? estimatedHardIron[0] : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return y coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronY() {
        return estimatedHardIron != null ? estimatedHardIron[1] : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias expressed in
     * Teslas (T).
     *
     * @return z coordinate of estimated magnetometer bias or null if not
     * available.
     */
    @Override
    public Double getEstimatedHardIronZ() {
        return estimatedHardIron != null ? estimatedHardIron[2] : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @return x coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronXAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[0], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets x coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[0]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @return y coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronYAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[1], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets y coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[1]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @return z coordinate of estimated magnetometer bias.
     */
    @Override
    public MagneticFluxDensity getEstimatedHardIronZAsMagneticFluxDensity() {
        return estimatedHardIron != null
                ? new MagneticFluxDensity(estimatedHardIron[2], MagneticFluxDensityUnit.TESLA) : null;
    }

    /**
     * Gets z coordinate of estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        if (estimatedHardIron != null) {
            result.setValue(estimatedHardIron[2]);
            result.setUnit(MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @return estimated magnetometer bias or null if not available.
     */
    @Override
    public MagneticFluxDensityTriad getEstimatedHardIronAsTriad() {
        return estimatedHardIron != null
                ? new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA,
                estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2]) : null;
    }

    /**
     * Gets estimated magnetometer bias.
     *
     * @param result instance where result will be stored.
     * @return true if estimated magnetometer bias is available and result was
     * modified, false otherwise.
     */
    @Override
    public boolean getEstimatedHardIronAsTriad(final MagneticFluxDensityTriad result) {
        if (estimatedHardIron != null) {
            result.setValueCoordinatesAndUnit(
                    estimatedHardIron[0], estimatedHardIron[1], estimatedHardIron[2], MagneticFluxDensityUnit.TESLA);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets position where body magnetic flux density measurements have been
     * taken.
     *
     * @return position where body magnetic flux density measurements have
     * been taken.
     */
    public NEDPosition getNedPosition() {
        return position;
    }

    /**
     * Sets position where body magnetic flux density measurements have been
     * taken.
     *
     * @param position position where body magnetic flux density measurements
     *                 have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final NEDPosition position) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.position = position;
    }

    /**
     * Gets position where body magnetic flux density measurements have been
     * taken expressed in ECEF coordinates.
     *
     * @return position where body magnetic flux density measurements have
     * been taken or null if not available.
     */
    public ECEFPosition getEcefPosition() {
        if (position != null) {
            final var result = new ECEFPosition();
            getEcefPosition(result);
            return result;
        } else {
            return null;
        }
    }

    /**
     * Gets position where body magnetic flux density measurements have been
     * taken expressed in ECEF coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if ECEF position could be computed, false otherwise.
     */
    public boolean getEcefPosition(final ECEFPosition result) {

        if (position != null) {
            final var velocity = new ECEFVelocity();
            NEDtoECEFPositionVelocityConverter.convertNEDtoECEF(
                    position.getLatitude(), position.getLongitude(), position.getHeight(),
                    0.0, 0.0, 0.0, result, velocity);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Sets position where body magnetic flux density measurements have been
     * taken expressed in ECEF coordinates.
     *
     * @param position position where body magnetic flux density have been
     *                 taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final ECEFPosition position) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.position = convertPosition(position);
    }

    /**
     * Gets timestamp expressed as decimal year where magnetic flux density
     * measurements have been measured.
     *
     * @return timestamp expressed as decimal year or null if not defined.
     */
    public Double getYear() {
        return year;
    }

    /**
     * Sets timestamp expressed as decimal year where magnetic flux density
     * measurements have been measured.
     *
     * @param year timestamp expressed as decimal year.
     * @throws LockedException if calibrator is currently running.
     */
    public void setYear(final Double year) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.year = year;
    }

    /**
     * Sets timestamp when magnetic flux density measurements have been
     * measured.
     *
     * @param timestampMillis a timestamp expressed in milliseconds since
     *                        epoch time (January 1st, 1970 at midnight).
     * @throws LockedException if calibrator is currently running.
     */
    public void setTime(final Long timestampMillis) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        year = convertTime(timestampMillis);
    }

    /**
     * Sets timestamp when magnetic flux density measurements have been
     * measured.
     *
     * @param date a date instance containing a timestamp.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTime(final Date date) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        year = convertTime(date);
    }

    /**
     * Sets timestamp when magnetic flux density measurements have been
     * measured.
     *
     * @param calendar a calendar instance containing a timestamp.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTime(final GregorianCalendar calendar) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        year = convertTime(calendar);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public List<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {
        return measurements;
    }

    /**
     * Sets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @param measurements collection of body magnetic flux density
     *                     measurements at a known position and timestamp
     *                     with unknown orientations.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final List<StandardDeviationBodyMagneticFluxDensity> measurements)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public MagnetometerCalibratorMeasurementType getMeasurementType() {
        return MagnetometerCalibratorMeasurementType.STANDARD_DEVIATION_BODY_MAGNETIC_FLUX_DENSITY;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return true;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer.
     * When enabled, this eliminates 3 variables from Mm (soft-iron) matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer, false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Mm matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for
     *                       accelerometer, gyroscope and magnetometer, false
     *                       otherwise.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this calibrator.
     *
     * @return listener to handle events raised by this calibrator.
     */
    public RobustKnownHardIronPositionAndInstantMagnetometerCalibratorListener getListener() {

}

    /**
     * Gets variance of estimated x coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated x coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasXVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasXStandardDeviation() {
        final var variance = getEstimatedBiasXVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasXStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasXStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasXStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasXStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated y coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasYVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasYStandardDeviation() {
        final var variance = getEstimatedBiasYVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasYStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasYStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasYStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasYStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated z coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasZVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasZStandardDeviation() {
        final var variance = getEstimatedBiasZVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasZStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasZStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasZStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasZStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @return standard deviation of estimated gyroscope bias coordinates.
     */
    public AngularSpeedTriad getEstimatedBiasStandardDeviation() {
        return estimatedCovariance != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                getEstimatedBiasXStandardDeviation(),
                getEstimatedBiasYStandardDeviation(),
                getEstimatedBiasZStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of gyroscope bias was available, false
     * otherwise.
     */
    public boolean getEstimatedBiasStandardDeviation(final AngularSpeedTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedBiasXStandardDeviation(),
                    getEstimatedBiasYStandardDeviation(),
                    getEstimatedBiasZStandardDeviation(),
                    AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates expressed
     * in radians per second (rad/s).
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null
     * if not available.
     */
    public Double getEstimatedBiasStandardDeviationAverage() {
        return estimatedCovariance != null
                ? (getEstimatedBiasXStandardDeviation() + getEstimatedBiasYStandardDeviation()
                + getEstimatedBiasZStandardDeviation()) / 3.0
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationAverageAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationAverage(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationAverageAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationAverage());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias expressed in
     * radians per second (rad/s).
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    @Override
    public Double getEstimatedBiasStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedBiasXVariance() + getEstimatedBiasYVariance() + getEstimatedBiasZVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationNormAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationNorm(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias coordinates.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of gyroscope bias is
     * available, false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationNormAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationNorm());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurementsOrSequences()}.
     *
     * @return size of subsets to be checked during robust estimation.
     */
    public int getPreliminarySubsetSize() {
        return preliminarySubsetSize;
    }

    /**
     * Sets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurementsOrSequences}.
     *
     * @param preliminarySubsetSize size of subsets to be checked during robust estimation.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is less than
     *                                  {@link #getMinimumRequiredMeasurementsOrSequences}.
     */
    public void setPreliminarySubsetSize(final int preliminarySubsetSize) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (preliminarySubsetSize < getMinimumRequiredMeasurementsOrSequences()) {
            throw new IllegalArgumentException();
        }

        this.preliminarySubsetSize = preliminarySubsetSize;
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    public abstract RobustEstimatorMethod getMethod();

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param method robust estimator method.
     * @return a robust gyroscope calibrator.
     */
    public static RobustEasyGyroscopeCalibrator create(final RobustEstimatorMethod method) {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @return constant rotation rate of turntable.
     */
    public double getTurntableRotationRate() {
        return turntableRotationRate;
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final double turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (turntableRotationRate <= 0.0) {
            throw new IllegalArgumentException();
        }

        this.turntableRotationRate = turntableRotationRate;
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @return constant rotation rate of turntable.
     */
    public AngularSpeed getTurntableRotationRateAsAngularSpeed() {
        return new AngularSpeed(turntableRotationRate, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @param result instance where result will be stored.
     */
    public void getTurntableRotationRateAsAngularSpeed(final AngularSpeed result) {
        result.setValue(turntableRotationRate);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final AngularSpeed turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTurntableRotationRate(convertAngularSpeed(turntableRotationRate));
    }

    /**
     * Gets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @return time interval between measurements.
     */
    public double getTimeInterval() {
        return timeInterval;
    }

    /**
     * Sets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTimeInterval(final double timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (timeInterval <= 0.0) {
            throw new IllegalArgumentException();
        }
        this.timeInterval = timeInterval;
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @return time interval between measurements.
     */
    public Time getTimeIntervalAsTime() {
        return new Time(timeInterval, TimeUnit.SECOND);
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @param result instance where result will be stored.
     */
    public void getTimeIntervalAsTime(final Time result) {
        result.setValue(timeInterval);
        result.setUnit(TimeUnit.SECOND);
    }

    /**
     * Sets time interval between measurements being captured.
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTimeInterval(final Time timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTimeInterval(convertTime(timeInterval));
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyKinematics> getMeasurements() {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @return constant rotation rate of turntable.
     */
    public double getTurntableRotationRate() {
        return turntableRotationRate;
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     * This is expressed in radians per second (rad/s).
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(
            final double turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (turntableRotationRate <= 0.0) {
            throw new IllegalArgumentException();
        }

        this.turntableRotationRate = turntableRotationRate;
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @return constant rotation rate of turntable.
     */
    public AngularSpeed getTurntableRotationRateAsAngularSpeed() {
        return new AngularSpeed(turntableRotationRate, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets constant rotation rate at which the turntable is spinning.
     *
     * @param result instance where result will be stored.
     */
    public void getTurntableRotationRateAsAngularSpeed(final AngularSpeed result) {
        result.setValue(turntableRotationRate);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets constant rotation rate at which the turntable is spinning.
     *
     * @param turntableRotationRate constant rotation rate of turntable.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTurntableRotationRate(final AngularSpeed turntableRotationRate) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTurntableRotationRate(convertAngularSpeed(turntableRotationRate));
    }

    /**
     * Gets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @return time interval between measurements.
     */
    public double getTimeInterval() {
        return timeInterval;
    }

    /**
     * Sets time interval between measurements being captured expressed in
     * seconds (s).
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is zero or
     *                                  negative.
     */
    public void setTimeInterval(final double timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (timeInterval <= 0.0) {
            throw new IllegalArgumentException();
        }
        this.timeInterval = timeInterval;
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @return time interval between measurements.
     */
    public Time getTimeIntervalAsTime() {
        return new Time(timeInterval, TimeUnit.SECOND);
    }

    /**
     * Gets time interval between measurements being captured.
     *
     * @param result instance where result will be stored.
     */
    public void getTimeIntervalAsTime(final Time result) {
        result.setValue(timeInterval);
        result.setUnit(TimeUnit.SECOND);
    }

    /**
     * Sets time interval between measurements being captured.
     *
     * @param timeInterval time interval between measurements.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTimeInterval(final Time timeInterval) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setTimeInterval(convertTime(timeInterval));
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public List<StandardDeviationBodyKinematics> getMeasurements() {

}

    /**
     * Gets variance of estimated x coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated x coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasXVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasXStandardDeviation() {
        final var variance = getEstimatedBiasXVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasXStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasXStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasXStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasXStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated y coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasYVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasYStandardDeviation() {
        final var variance = getEstimatedBiasYVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasYStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasYStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasYStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasYStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated z coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasZVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasZStandardDeviation() {
        final var variance = getEstimatedBiasZVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasZStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasZStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasZStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasZStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @return standard deviation of estimated gyroscope bias coordinates.
     */
    public AngularSpeedTriad getEstimatedBiasStandardDeviation() {
        return estimatedCovariance != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                getEstimatedBiasXStandardDeviation(),
                getEstimatedBiasYStandardDeviation(),
                getEstimatedBiasZStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of gyroscope bias was available, false
     * otherwise.
     */
    public boolean getEstimatedBiasStandardDeviation(final AngularSpeedTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedBiasXStandardDeviation(),
                    getEstimatedBiasYStandardDeviation(),
                    getEstimatedBiasZStandardDeviation(),
                    AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates expressed
     * in radians per second (rad/s).
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null
     * if not available.
     */
    public Double getEstimatedBiasStandardDeviationAverage() {
        return estimatedCovariance != null
                ? (getEstimatedBiasXStandardDeviation() + getEstimatedBiasYStandardDeviation()
                + getEstimatedBiasZStandardDeviation()) / 3.0
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationAverageAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationAverage(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationAverageAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationAverage());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias expressed in
     * radians per second (rad/s).
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    @Override
    public Double getEstimatedBiasStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedBiasXVariance() + getEstimatedBiasYVariance() + getEstimatedBiasZVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationNormAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationNorm(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias coordinates.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of gyroscope bias is
     * available, false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationNormAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationNorm());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurementsOrSequences()}.
     *
     * @return size of subsets to be checked during robust estimation.
     */
    public int getPreliminarySubsetSize() {
        return preliminarySubsetSize;
    }

    /**
     * Sets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurementsOrSequences}.
     *
     * @param preliminarySubsetSize size of subsets to be checked during robust estimation.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is less than
     *                                  {@link #getMinimumRequiredMeasurementsOrSequences}.
     */
    public void setPreliminarySubsetSize(final int preliminarySubsetSize) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (preliminarySubsetSize < getMinimumRequiredMeasurementsOrSequences()) {

public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets variance of estimated x coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated x coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasXVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(0, 0) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasXStandardDeviation() {
        final var variance = getEstimatedBiasXVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated x coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasXStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasXStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated x coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated x coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasXStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasXStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated y coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated y coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasYVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(1, 1) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasYStandardDeviation() {
        final var variance = getEstimatedBiasYVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated y coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasYStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasYStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated y coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated y coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasYStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasYStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets variance of estimated z coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated z coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasZVariance() {
        return estimatedCovariance != null ? estimatedCovariance.getElementAt(2, 2) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias expressed in
     * radians per second (rad/s).
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public Double getEstimatedBiasZStandardDeviation() {
        final var variance = getEstimatedBiasZVariance();
        return variance != null ? Math.sqrt(variance) : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @return standard deviation of estimated z coordinate of gyroscope bias or null if not
     * available.
     */
    public AngularSpeed getEstimatedBiasZStandardDeviationAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasZStandardDeviation(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets standard deviation of estimated z coordinate of gyroscope bias.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of estimated z coordinate of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasZStandardDeviationAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasZStandardDeviation());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @return standard deviation of estimated gyroscope bias coordinates.
     */
    public AngularSpeedTriad getEstimatedBiasStandardDeviation() {
        return estimatedCovariance != null
                ? new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND,
                getEstimatedBiasXStandardDeviation(),
                getEstimatedBiasYStandardDeviation(),
                getEstimatedBiasZStandardDeviation())
                : null;
    }

    /**
     * Gets standard deviation of estimated gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if standard deviation of gyroscope bias was available, false
     * otherwise.
     */
    public boolean getEstimatedBiasStandardDeviation(final AngularSpeedTriad result) {
        if (estimatedCovariance != null) {
            result.setValueCoordinatesAndUnit(
                    getEstimatedBiasXStandardDeviation(),
                    getEstimatedBiasYStandardDeviation(),
                    getEstimatedBiasZStandardDeviation(),
                    AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates expressed
     * in radians per second (rad/s).
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null
     * if not available.
     */
    public Double getEstimatedBiasStandardDeviationAverage() {
        return estimatedCovariance != null
                ? (getEstimatedBiasXStandardDeviation() + getEstimatedBiasYStandardDeviation()
                + getEstimatedBiasZStandardDeviation()) / 3.0 : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @return average of estimated standard deviation of gyroscope bias coordinates or null.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationAverageAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationAverage(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets average of estimated standard deviation of gyroscope bias coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if average of estimated standard deviation of gyroscope bias is available,
     * false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationAverageAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationAverage());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias expressed in
     * radians per second (rad/s).
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    @Override
    public Double getEstimatedBiasStandardDeviationNorm() {
        return estimatedCovariance != null
                ? Math.sqrt(getEstimatedBiasXVariance() + getEstimatedBiasYVariance() + getEstimatedBiasZVariance())
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @return norm of estimated standard deviation of gyroscope bias or null
     * if not available.
     */
    public AngularSpeed getEstimatedBiasStandardDeviationNormAsAngularSpeed() {
        return estimatedCovariance != null
                ? new AngularSpeed(getEstimatedBiasStandardDeviationNorm(), AngularSpeedUnit.RADIANS_PER_SECOND)
                : null;
    }

    /**
     * Gets norm of estimated standard deviation of gyroscope bias coordinates.
     * This can be used as the initial gyroscope bias uncertainty for
     * {@link INSLooselyCoupledKalmanInitializerConfig} or {@link INSTightlyCoupledKalmanInitializerConfig}.
     *
     * @param result instance where result will be stored.
     * @return true if norm of estimated standard deviation of gyroscope bias is
     * available, false otherwise.
     */
    public boolean getEstimatedBiasStandardDeviationNormAsAngularSpeed(final AngularSpeed result) {
        if (estimatedCovariance != null) {
            result.setValue(getEstimatedBiasStandardDeviationNorm());
            result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
            return true;
        } else {
            return false;
        }
    }

this(convertPosition(position), measurements, commonAxisUsed, hardIron, initialMm, listener);
    }

    /**
     * Gets position where body magnetic flux density measurements have been
     * taken.
     *
     * @return position where body magnetic flux density measurements have
     * been taken.
     */
    public NEDPosition getNedPosition() {
        return position;
    }

    /**
     * Sets position where body magnetic flux density measurements have been
     * taken.
     *
     * @param position position where body magnetic flux density measurements
     *                 have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final NEDPosition position) throws LockedException {
        if (isRunning()) {
            throw new LockedException();
        }

        this.position = position;
    }

    /**
     * Gets position where body magnetic flux density measurements have been
     * taken expressed in ECEF coordinates.
     *
     * @return position where body magnetic flux density measurements have
     * been taken or null if not available.
     */
    public ECEFPosition getEcefPosition() {
        if (position != null) {
            final var result = new ECEFPosition();
            getEcefPosition(result);
            return result;
        } else {
            return null;
        }
    }

    /**
     * Gets position where body magnetic flux density measurements have been
     * taken expressed in ECEF coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if ECEF position could be computed, false otherwise.
     */
    public boolean getEcefPosition(final ECEFPosition result) {
        if (position != null) {
            final var velocity = new ECEFVelocity();
            NEDtoECEFPositionVelocityConverter.convertNEDtoECEF(
                    position.getLatitude(), position.getLongitude(), position.getHeight(),
                    0.0, 0.0, 0.0, result, velocity);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Sets position where body magnetic flux density measurements have been
     * taken expressed in ECEF coordinates.
     *
     * @param position position where body magnetic flux density have been
     *                 taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final ECEFPosition position) throws LockedException {
        if (isRunning()) {
            throw new LockedException();
        }

        this.position = convertPosition(position);
    }

    /**
     * Gets timestamp expressed as decimal year where magnetic flux density
     * measurements have been measured.
     *
     * @return timestamp expressed as decimal year or null if not defined.
     */
    public Double getYear() {
        return year;
    }

    /**
     * Sets timestamp expressed as decimal year where magnetic flux density
     * measurements have been measured.
     *
     * @param year timestamp expressed as decimal year.
     * @throws LockedException if calibrator is currently running.
     */
    public void setYear(final Double year) throws LockedException {
        if (isRunning()) {
            throw new LockedException();
        }
        this.year = year;
    }

    /**
     * Sets timestamp when magnetic flux density measurements have been
     * measured.
     *
     * @param timestampMillis a timestamp expressed in milliseconds since
     *                        epoch time (January 1st, 1970 at midnight).
     * @throws LockedException if calibrator is currently running.
     */
    public void setTime(final Long timestampMillis) throws LockedException {
        if (isRunning()) {
            throw new LockedException();
        }
        year = convertTime(timestampMillis);
    }

    /**
     * Sets timestamp when magnetic flux density measurements have been
     * measured.
     *
     * @param date a date instance containing a timestamp.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTime(final Date date) throws LockedException {
        if (isRunning()) {
            throw new LockedException();
        }
        year = convertTime(date);
    }

    /**
     * Sets timestamp when magnetic flux density measurements have been
     * measured.
     *
     * @param calendar a calendar instance containing a timestamp.
     * @throws LockedException if calibrator is currently running.
     */
    public void setTime(final GregorianCalendar calendar) throws LockedException {
        if (isRunning()) {
            throw new LockedException();
        }
        year = convertTime(calendar);
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && position != null && year != null;
    }

    /**
     * Gets Earth's magnetic model.
     *
     * @return Earth's magnetic model or null if not provided.
     */
    public WorldMagneticModel getMagneticModel() {
        return magneticModel;
    }

    /**
     * Sets Earth's magnetic model.
     *
     * @param magneticModel Earth's magnetic model to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setMagneticModel(final WorldMagneticModel magneticModel) throws LockedException {
        if (isRunning()) {
            throw new LockedException();
        }
        this.magneticModel = magneticModel;
    }

    /**
     * Called before calibration occurs.
     * This can be overridden by subclasses.
     *
     * @throws CalibrationException if anything fails.
     */
    @Override
    protected void onBeforeCalibrate() throws CalibrationException {
        computeGroundTruthMagneticFluxDensityNorm();
    }

    /**
     * Computes expected ground truth magnetic flux density norm based on World Magnetic Model.
     * Notice that actual magnetic field measured by devices might differ from this value, since it might be attenuated
     * or other devices might interfere.
     *
     * @throws CalibrationException if world magnetic model cannot be loaded.
     */
    private void computeGroundTruthMagneticFluxDensityNorm() throws CalibrationException {
        final WMMEarthMagneticFluxDensityEstimator wmmEstimator;
        if (magneticModel != null) {
            wmmEstimator = new WMMEarthMagneticFluxDensityEstimator(magneticModel);
        } else {
            try {
                wmmEstimator = new WMMEarthMagneticFluxDensityEstimator();
            } catch (final IOException e) {
                throw new CalibrationException(e);
            }
        }

        final var pos = getNedPosition();
        final var earthB = wmmEstimator.estimate(pos, year);
        groundTruthMagneticFluxDensityNorm = earthB.getNorm();
    }

    /**
     * Converts a time instance expressed in milliseconds since epoch time
     * (January 1st, 1970 at midnight) to a decimal year.
     *
     * @param timestampMillis milliseconds value to be converted.
     * @return converted value expressed in decimal years.
     */
    private static Double convertTime(final Long timestampMillis) {
        if (timestampMillis == null) {
            return null;
        }

        final var calendar = new GregorianCalendar();
        calendar.setTimeInMillis(timestampMillis);
        return convertTime(calendar);
    }

    /**
     * Converts a time instant contained ina date object to a
     * decimal year.
     *
     * @param date a time instance to be converted.
     * @return converted value expressed in decimal years.
     */
    private static Double convertTime(final Date date) {
        if (date == null) {
            return null;
        }

        final var calendar = new GregorianCalendar();
        calendar.setTime(date);
        return convertTime(calendar);
    }

    /**
     * Converts a time instant contained in a gregorian calendar to a
     * decimal year.
     *
     * @param calendar calendar containing a specific instant to be
     *                 converted.
     * @return converted value expressed in decimal years.
     */
    private static Double convertTime(final GregorianCalendar calendar) {
        if (calendar == null) {
            return null;
        }

        return WMMEarthMagneticFluxDensityEstimator.convertTime(calendar);
    }

    /**
     * Converts provided ECEF position to position expressed in NED
     * coordinates.
     *
     * @param position ECEF position to be converted.
     * @return converted position expressed in NED coordinates.
     */
    private static NEDPosition convertPosition(final ECEFPosition position) {
        final var velocity = new NEDVelocity();
        final var result = new NEDPosition();
        ECEFtoNEDPositionVelocityConverter.convertECEFtoNED(
                position.getX(), position.getY(), position.getZ(),
                0.0, 0.0, 0.0, result, velocity);
        return result;
    }
}

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyKinematics> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @param measurements collection of body kinematics measurements at a
     *                     known position with unknown orientations.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final Collection<StandardDeviationBodyKinematics> measurements) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public AccelerometerCalibratorMeasurementType getMeasurementType() {
        return AccelerometerCalibratorMeasurementType.STANDARD_DEVIATION_BODY_KINEMATICS;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return false;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return false;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    public L getListener() {
        return listener;
    }

    /**
     * Sets listener to handle events raised by this estimator.
     *
     * @param listener listener to handle events raised by this estimator.
     * @throws LockedException if calibrator is currently running.
     */
    public void setListener(final L listener) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurements() {
        return commonAxisUsed ? MINIMUM_MEASUREMENTS_COMMON_Z_AXIS : MINIMUM_MEASUREMENTS_GENERAL;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= getMinimumRequiredMeasurements()
                && groundTruthGravityNorm != null;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }

        if (!isReady()) {
            throw new NotReadyException();
        }

        try {
            running = true;

            if (listener != null) {
                //noinspection unchecked
                listener.onCalibrateStart((C) this);
            }

            if (commonAxisUsed) {
                calibrateCommonAxis();
            } else {
                calibrateGeneral();
            }

            if (listener != null) {
                //noinspection unchecked
                listener.onCalibrateEnd((C) this);
            }

        } catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {

hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {
        return measurements;
    }

    /**
     * Sets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @param measurements collection of body magnetic flux density
     *                     measurements at a known position and timestamp
     *                     with unknown orientations.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final Collection<StandardDeviationBodyMagneticFluxDensity> measurements)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public MagnetometerCalibratorMeasurementType getMeasurementType() {
        return MagnetometerCalibratorMeasurementType.STANDARD_DEVIATION_BODY_MAGNETIC_FLUX_DENSITY;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return false;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return false;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer.
     * When enabled, this eliminates 3 variables from Mm (soft-iron) matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer, false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Mm matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for
     *                       accelerometer, gyroscope and magnetometer, false
     *                       otherwise.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this calibrator.
     *
     * @return listener to handle events raised by this calibrator.
     */
    public L getListener() {
        return listener;
    }

    /**
     * Sets listener to handle events raised by this calibrator.
     *
     * @param listener listener to handle events raised by this calibrator.
     * @throws LockedException if calibrator is currently running.
     */
    public void setListener(final L listener) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurements() {
        return commonAxisUsed ? MINIMUM_MEASUREMENTS_COMMON_Z_AXIS : MINIMUM_MEASUREMENTS_GENERAL;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= getMinimumRequiredMeasurements();
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Estimates magnetometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if calibration fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }

        if (!isReady()) {
            throw new NotReadyException();
        }

        try {
            running = true;

            onBeforeCalibrate();

            if (listener != null) {
                //noinspection unchecked
                listener.onCalibrateStart((C) this);
            }

            if (commonAxisUsed) {
                calibrateCommonAxis();
            } else {
                calibrateGeneral();
            }

            if (listener != null) {
                //noinspection unchecked
                listener.onCalibrateEnd((C) this);
            }

        } catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {

public void setInitialBias(
            final AngularSpeed initialBiasX, final AngularSpeed initialBiasY, final AngularSpeed initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAngularSpeed(initialBiasX);
        this.initialBiasY = convertAngularSpeed(initialBiasY);
        this.initialBiasZ = convertAngularSpeed(initialBiasZ);
    }

    /**
     * Gets initial x scaling factor of gyroscope.
     *
     * @return initial x scaling factor of gyroscope.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor of gyroscope.
     *
     * @return initial y scaling factor of gyroscope.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor of gyroscope.
     *
     * @param initialSy initial y scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor of gyroscope.
     *
     * @return initial z scaling factor of gyroscope.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor of gyroscope.
     *
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error of gyroscope.
     *
     * @return initial x-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error of gyroscope.
     *
     * @return initial x-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error of gyroscope.
     *
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error of gyroscope.
     *
     * @return initial y-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error of gyroscope.
     *
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error of gyroscope.
     *
     * @return initial y-z cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error of gyroscope.
     *
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error of gyroscope.
     *
     * @return initial z-x cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error of gyroscope.
     *
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error of gyroscope.
     *
     * @return initial z-y cross coupling error of gyroscope.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error of gyroscope.
     *
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors of gyroscope.
     *
     * @param initialSx initial x scaling factor of gyroscope.
     * @param initialSy initial y scaling factor of gyroscope.
     * @param initialSz initial z scaling factor of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors of gyroscope.
     *
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors of
     * gyroscope.
     *
     * @param initialSx  initial x scaling factor of gyroscope.
     * @param initialSy  initial y scaling factor of gyroscope.
     * @param initialSz  initial z scaling factor of gyroscope.
     * @param initialMxy initial x-y cross coupling error of gyroscope.
     * @param initialMxz initial x-z cross coupling error of gyroscope.
     * @param initialMyx initial y-x cross coupling error of gyroscope.
     * @param initialMyz initial y-z cross coupling error of gyroscope.
     * @param initialMzx initial z-x cross coupling error of gyroscope.
     * @param initialMzy initial z-y cross coupling error of gyroscope.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

if (estimatedMg == null) {
            estimatedMg = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        } else {
            estimatedMg.initialize(0.0);
        }

        estimatedMg.setElementAt(0, 0, sx);
        estimatedMg.setElementAt(1, 0, myx);
        estimatedMg.setElementAt(2, 0, mzx);

        estimatedMg.setElementAt(0, 1, mxy);
        estimatedMg.setElementAt(1, 1, sy);
        estimatedMg.setElementAt(2, 1, mzy);

        estimatedMg.setElementAt(0, 2, mxz);
        estimatedMg.setElementAt(1, 2, myz);
        estimatedMg.setElementAt(2, 2, sz);

        if (estimatedGg == null) {
            estimatedGg = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        } else {
            estimatedGg.initialize(0.0);
        }

        estimatedGg.setElementAtIndex(0, g11);
        estimatedGg.setElementAtIndex(1, g21);
        estimatedGg.setElementAtIndex(2, g31);
        estimatedGg.setElementAtIndex(3, g12);
        estimatedGg.setElementAtIndex(4, g22);
        estimatedGg.setElementAtIndex(5, g32);
        estimatedGg.setElementAtIndex(6, g13);
        estimatedGg.setElementAtIndex(7, g23);
        estimatedGg.setElementAtIndex(8, g33);

        estimatedCovariance = fitter.getCovar();
        estimatedChiSq = fitter.getChisq();
        estimatedMse = fitter.getMse();
    }

    /**
     * Sets input data into Levenberg-Marquardt fitter.
     *
     * @throws WrongSizeException never happens.
     */
    private void setInputData() throws WrongSizeException {
        // set input data using:
        // Ωmeasx = bx + Ωtruex + sx * Ωtruex + mxy * Ωtruey + mxz * Ωtruez + g11 * ftruex + g12 * ftruey + g13 * ftruez
        // Ωmeasy = by + myx * Ωtruex + Ωtruey + sy * Ωtruey + myz * Ωtruez + g21 * ftruex * g22 * ftruey + g23 * ftruez
        // Ωmeasz = bz + mzx * Ωtruex + mzy * Ωtruey + Ωtruez + sz * Ωtruez + g31 * ftruex + g32 * ftruey + g33 * ftruez

        // fmeasx = bx + ftruex + sx * ftruex + mxy * ftruey + mxz * ftruez
        // fmeasy = by + myx * ftruex + ftruey + sy * ftruey + myz * ftruez
        // fmeasz = bz + mzx * ftruex + mzy * ftruey + ftruez + sz * ftruez

        final var expectedKinematics = new BodyKinematics();

        final var numMeasurements = measurements.size();
        final var x = new Matrix(numMeasurements, 2 * BodyKinematics.COMPONENTS);
        final var y = new Matrix(numMeasurements, BodyKinematics.COMPONENTS);
        final var standardDeviations = new double[numMeasurements];
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredKinematics = measurement.getKinematics();
            final var ecefFrame = measurement.getFrame();
            final var previousEcefFrame = measurement.getPreviousFrame();
            final var timeInterval = measurement.getTimeInterval();

            ECEFKinematicsEstimator.estimateKinematics(timeInterval, ecefFrame, previousEcefFrame, expectedKinematics);

            final var omegaMeasX = measuredKinematics.getAngularRateX();
            final var omegaMeasY = measuredKinematics.getAngularRateY();
            final var omegaMeasZ = measuredKinematics.getAngularRateZ();

            final var omegaTrueX = expectedKinematics.getAngularRateX();
            final var omegaTrueY = expectedKinematics.getAngularRateY();
            final var omegaTrueZ = expectedKinematics.getAngularRateZ();

            final var fTrueX = expectedKinematics.getFx();
            final var fTrueY = expectedKinematics.getFy();
            final var fTrueZ = expectedKinematics.getFz();

            x.setElementAt(i, 0, omegaTrueX);
            x.setElementAt(i, 1, omegaTrueY);
            x.setElementAt(i, 2, omegaTrueZ);

            x.setElementAt(i, 3, fTrueX);
            x.setElementAt(i, 4, fTrueY);
            x.setElementAt(i, 5, fTrueZ);

            y.setElementAt(i, 0, omegaMeasX);
            y.setElementAt(i, 1, omegaMeasY);
            y.setElementAt(i, 2, omegaMeasZ);

            standardDeviations[i] = measurement.getAngularRateStandardDeviation();
            i++;
        }

        fitter.setInputData(x, y, standardDeviations);
    }

    /**
     * Converts angular speed instance to radians per second (rad/s).
     *
     * @param value angular speed value.
     * @param unit  unit of angular speed value.
     * @return converted value.
     */
    private static double convertAngularSpeed(final double value, final AngularSpeedUnit unit) {
        return AngularSpeedConverter.convert(value, unit, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Converts angular speed instance to radians per second (rad/s).
     *
     * @param angularSpeed angular speed instance to be converted.
     * @return converted value.
     */
    private static double convertAngularSpeed(final AngularSpeed angularSpeed) {
        return convertAngularSpeed(angularSpeed.getValue().doubleValue(), angularSpeed.getUnit());
    }
}

return sequences != null && sequences.size() >= getMinimumRequiredMeasurementsOrSequences();
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32, gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurementsOrSequences()}.
     *
     * @return size of subsets to be checked during robust estimation.
     */
    public int getPreliminarySubsetSize() {
        return preliminarySubsetSize;
    }

    /**
     * Sets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurementsOrSequences}.
     *
     * @param preliminarySubsetSize size of subsets to be checked during robust estimation.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is less than
     *                                  {@link #getMinimumRequiredMeasurementsOrSequences}.
     */
    public void setPreliminarySubsetSize(final int preliminarySubsetSize) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (preliminarySubsetSize < getMinimumRequiredMeasurementsOrSequences()) {
            throw new IllegalArgumentException();
        }

        this.preliminarySubsetSize = preliminarySubsetSize;
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    public abstract RobustEstimatorMethod getMethod();

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param method robust estimator method.
     * @return a robust gyroscope calibrator.
     */
    public static RobustKnownBiasEasyGyroscopeCalibrator create(final RobustEstimatorMethod method) {

&& groundTruthGravityNorm != null;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {
        return estimatedMa;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration solution.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy.
     * This is only available when result has been refined and covariance
     * is kept.
     *
     * @return estimated covariance matrix for estimated position.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurements()}.
     *
     * @return size of subsets to be checked during robust estimation.
     */
    public int getPreliminarySubsetSize() {
        return preliminarySubsetSize;
    }

    /**
     * Sets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #getMinimumRequiredMeasurements()}.
     *
     * @param preliminarySubsetSize size of subsets to be checked during robust estimation.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is less than {@link #getMinimumRequiredMeasurements()}.
     */
    public void setPreliminarySubsetSize(final int preliminarySubsetSize) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (preliminarySubsetSize < getMinimumRequiredMeasurements()) {
            throw new IllegalArgumentException();
        }

        this.preliminarySubsetSize = preliminarySubsetSize;
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    public abstract RobustEstimatorMethod getMethod();

    /**
     * Creates a robust accelerometer calibrator.
     *
     * @param method robust estimator method.
     * @return a robust accelerometer calibrator.
     */
    public static RobustKnownBiasAndGravityNormAccelerometerCalibrator create(final RobustEstimatorMethod method) {

this.listener = listener;
    }

    /**
     * Gets known x coordinate of accelerometer bias expressed in meters per squared
     * second (m/s^2).
     *
     * @return x coordinate of accelerometer bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets known x coordinate of accelerometer bias expressed in meters per squared
     * second (m/s^2).
     *
     * @param biasX x coordinate of accelerometer bias.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets known y coordinate of accelerometer bias expressed in meters per squared
     * second (m/s^2).
     *
     * @return y coordinate of accelerometer bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets known y coordinate of accelerometer bias expressed in meters per squared
     * second (m/s^2).
     *
     * @param biasY y coordinate of accelerometer bias.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasY = biasY;
    }

    /**
     * Gets known z coordinate of accelerometer bias expressed in meters per squared
     * second (m/s^2).
     *
     * @return z coordinate of accelerometer bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets known z coordinate of accelerometer bias expressed in meters per squared
     * second (m/s^2).
     *
     * @param biasZ z coordinate of accelerometer bias.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasZ = biasZ;
    }

    /**
     * Gets known x coordinate of accelerometer bias.
     *
     * @return x coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getBiasXAsAcceleration() {
        return new Acceleration(biasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known x coordinate of accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasXAsAcceleration(final Acceleration result) {
        result.setValue(biasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known x coordinate of accelerometer bias.
     *
     * @param biasX x coordinate of accelerometer bias.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setBiasX(final Acceleration biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasX = convertAcceleration(biasX);
    }

    /**
     * Gets known y coordinate of accelerometer bias.
     *
     * @return y coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getBiasYAsAcceleration() {
        return new Acceleration(biasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known y coordinate of accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasYAsAcceleration(final Acceleration result) {
        result.setValue(biasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known y coordinate of accelerometer bias.
     *
     * @param biasY y coordinate of accelerometer bias.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setBiasY(final Acceleration biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasY = convertAcceleration(biasY);
    }

    /**
     * Gets known z coordinate of accelerometer bias.
     *
     * @return z coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getBiasZAsAcceleration() {
        return new Acceleration(biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets known z coordinate of accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasZAsAcceleration(final Acceleration result) {
        result.setValue(biasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known z coordinate of accelerometer bias.
     *
     * @param biasZ z coordinate of accelerometer bias.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setBiasZ(final Acceleration biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Sets known accelerometer bias coordinates expressed in meters per squared
     * second (m/s^2).
     *
     * @param biasX x coordinate of accelerometer bias.
     * @param biasY y coordinate of accelerometer bias.
     * @param biasZ z coordinate of accelerometer bias.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setBiasCoordinates(final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasX = biasX;
        this.biasY = biasY;
        this.biasZ = biasZ;
    }

    /**
     * Sets known accelerometer bias coordinates.
     *
     * @param biasX z coordinate of accelerometer bias.
     * @param biasY y coordinate of accelerometer bias.
     * @param biasZ z coordinate of accelerometer bias.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setBiasCoordinates(final Acceleration biasX, final Acceleration biasY, final Acceleration biasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasX = convertAcceleration(biasX);
        this.biasY = convertAcceleration(biasY);
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @return known accelerometer bias.
     */
    @Override
    public AccelerationTriad getBiasAsTriad() {
        return new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getBiasAsTriad(final AccelerationTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known accelerometer bias.
     *
     * @param bias accelerometer bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBias(final AccelerationTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAcceleration(bias.getValueX(), bias.getUnit());
        biasY = convertAcceleration(bias.getValueY(), bias.getUnit());
        biasZ = convertAcceleration(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {

setResult(m, b, g);

        // at this point covariance is expressed in terms of b, M and G, and must
        // be expressed in terms of bg, Mg and Gg.
        // We know that:
        // bg = M * b
        // Mg = M - I
        // Gg = M * G

        // b = [bx]
        //     [by]
        //     [bz]

        // M = [m11  m12  m13]
        //     [0    m22  m23]
        //     [0    0    m33]

        // G = [g11  g12  g13]
        //     [g21  g22  g23]
        //     [g31  g32  g33]

        // bg = [m11  m12  m13][bx] = [m11 * bx + m12 * by + m13 * bz] = [bgx]
        //      [0    m22  m23][by]   [           m22 * by + m23 * bz]   [bgy]
        //      [0    0    m33][bz]   [                      m33 * bz]   [bgz]

        // Mg = [sx  mxy  mxz] = [m11 - 1    m12         m13     ]
        //      [myx sy	  myz]   [0          m22 - 1     m23     ]
        //      [mzx mzy  sz ]   [0          0           m33 - 1 ]

        // Gg = [gg11  gg12  gg13] = [m11  m12  m13][g11  g12  g13]
        //      [gg21  gg22  gg23]   [0    m22  m23][g21  g22  g23]
        //      [gg31  gg32  gg33]   [0    0    m33][g31  g32  g33]

        // Defining the linear application:
        // F(b, M, G) = F(bx, by, bz, m11, m12, m22, m13, m23, m33, g11, g21, g31, g12, g22, g32, g13, g23, g33)
        // as:
        // [bgx] =  [m11 * bx + m12 * by + m13 * bz]
        // [bgy]    [           m22 * by + m23 * bz]
        // [bgz]    [                      m33 * bz]
        // [sx]     [m11 - 1]
        // [sy]     [m22 - 1]
        // [sz]     [m33 - 1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [0]
        // [myz]    [m23]
        // [mzx]    [0]
        // [mzy]    [0]
        // [gg11]   [m11 * g11 + m12 * g21 + m13 * g31]
        // [gg21]   [            m22 * g21 + m23 * g31]
        // [gg31]   [                        m33 * g31]
        // [gg12]   [m11 * g12 + m12 * g22 + m13 * g32]
        // [gg22]   [            m22 * g22 + m23 * g32]
        // [gg32]   [                        m33 * g32]
        // [gg13]   [m11 * g13 + m12 * g23 + m13 * g33]
        // [gg23]   [            m22 * g23 + m23 * g33]
        // [gg33]   [                        m33 * g33]

        // Then the Jacobian of F(b, M, G) is:
        // J = [m11  m12  m13  bx   by   0    bz   0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    m22  m23  0    0    by   0    bz   0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    m33  0    0    0    0    0    bz   0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    1    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    g11  g21  0    g31  0    0    m11  m12  m13  0    0    0    0    0    0  ]
        //     [0    0    0    0    0    g21  0    g31  0    0    m22  m23  0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    g31  0    0    m33  0    0    0    0    0    0  ]
        //     [0    0    0    g12  g22  0    g32  0    0    0    0    0    m11  m12  m13  0    0    0  ]
        //     [0    0    0    0    0    g22  0    g32  0    0    0    0    0    m22  m23  0    0    0  ]
        //     [0    0    0    0    0    0    0    0    g32  0    0    0    0    0    m33  0    0    0  ]
        //     [0    0    0    g13  g23  0    g33  0    0    0    0    0    0    0    0    m11  m12  m13]
        //     [0    0    0    0    0    g23  0    g33  0    0    0    0    0    0    0    0    m22  m23]
        //     [0    0    0    0    0    0    0    0    g33  0    0    0    0    0    0    0    0    m33]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS_AND_CROSS_BIASES, COMMON_Z_AXIS_UNKNOWNS_AND_CROSS_BIASES);

        jacobian.setElementAt(0, 0, m11);
        jacobian.setElementAt(0, 1, m12);
        jacobian.setElementAt(0, 2, m13);
        jacobian.setElementAt(0, 3, bx);
        jacobian.setElementAt(0, 4, by);
        jacobian.setElementAt(0, 6, bz);

        jacobian.setElementAt(1, 1, m22);
        jacobian.setElementAt(1, 2, m23);
        jacobian.setElementAt(1, 5, by);
        jacobian.setElementAt(1, 7, bz);

        jacobian.setElementAt(2, 2, m33);
        jacobian.setElementAt(2, 8, bz);

        jacobian.setElementAt(3, 3, 1.0);
        jacobian.setElementAt(4, 5, 1.0);
        jacobian.setElementAt(5, 8, 1.0);

        jacobian.setElementAt(6, 4, 1.0);
        jacobian.setElementAt(7, 6, 1.0);

        jacobian.setElementAt(9, 7, 1.0);

        jacobian.setElementAt(12, 3, g11);
        jacobian.setElementAt(12, 4, g21);
        jacobian.setElementAt(12, 6, g31);
        jacobian.setElementAt(12, 9, m11);
        jacobian.setElementAt(12, 10, m12);
        jacobian.setElementAt(12, 11, m13);

        jacobian.setElementAt(13, 5, g21);
        jacobian.setElementAt(13, 7, g31);
        jacobian.setElementAt(13, 10, m22);
        jacobian.setElementAt(13, 11, m23);

        jacobian.setElementAt(14, 8, g31);
        jacobian.setElementAt(14, 11, m33);

        jacobian.setElementAt(15, 3, g12);
        jacobian.setElementAt(15, 4, g22);
        jacobian.setElementAt(15, 6, g32);
        jacobian.setElementAt(15, 12, m11);
        jacobian.setElementAt(15, 13, m12);
        jacobian.setElementAt(15, 14, m13);

        jacobian.setElementAt(16, 5, g22);
        jacobian.setElementAt(16, 7, g32);
        jacobian.setElementAt(16, 13, m22);
        jacobian.setElementAt(16, 14, m23);

        jacobian.setElementAt(17, 8, g32);
        jacobian.setElementAt(17, 14, m33);

        jacobian.setElementAt(18, 3, g13);
        jacobian.setElementAt(18, 4, g23);
        jacobian.setElementAt(18, 6, g33);
        jacobian.setElementAt(18, 15, m11);
        jacobian.setElementAt(18, 16, m12);
        jacobian.setElementAt(18, 17, m13);

        jacobian.setElementAt(19, 5, g23);
        jacobian.setElementAt(19, 7, g33);
        jacobian.setElementAt(19, 16, m22);
        jacobian.setElementAt(19, 17, m23);

        jacobian.setElementAt(20, 8, g33);
        jacobian.setElementAt(20, 17, m33);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Internal method to perform general calibration when G-dependent cross
     * biases are being estimated.
     *
     * @throws AlgebraException                         if accelerometer parameters prevent fixing
     *                                                  measured accelerometer values due to numerical instabilities.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateGeneralAndGDependentCrossBiases() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {

}

    /**
     * Gets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = biasY;
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = biasZ;
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasXAsAcceleration() {
        return new Acceleration(biasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasXAsAcceleration(final Acceleration result) {
        result.setValue(biasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final Acceleration biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAcceleration(biasX);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasYAsAcceleration() {
        return new Acceleration(biasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasYAsAcceleration(final Acceleration result) {
        result.setValue(biasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final Acceleration biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = convertAcceleration(biasY);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasZAsAcceleration() {
        return new Acceleration(biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasZAsAcceleration(final Acceleration result) {
        result.setValue(biasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets z-coordinate of known accelerometer bias to be used to find a solution.
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final Acceleration biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Sets known bias coordinates of accelerometer expressed in meters
     * per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @param biasY y-coordinate of known accelerometer bias.
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
        this.biasY = biasY;
        this.biasZ = biasZ;
    }

    /**
     * Sets known bias coordinates of accelerometer.
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @param biasY y-coordinate of known accelerometer bias.
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(
            final Acceleration biasX, final Acceleration biasY, final Acceleration biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAcceleration(biasX);
        this.biasY = convertAcceleration(biasY);
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @return known accelerometer bias.
     */
    @Override
    public AccelerationTriad getBiasAsTriad() {
        return new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getBiasAsTriad(final AccelerationTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known accelerometer bias.
     *
     * @param bias accelerometer bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBias(final AccelerationTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAcceleration(bias.getValueX(), bias.getUnit());
        biasY = convertAcceleration(bias.getValueY(), bias.getUnit());
        biasZ = convertAcceleration(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {

}

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bx, by, bz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy.
     *
     * @return estimated covariance matrix for estimated calibration parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #MINIMUM_MEASUREMENTS_COMMON_Z_AXIS}.
     *
     * @return size of subsets to be checked during robust estimation.
     */
    public int getPreliminarySubsetSize() {
        return preliminarySubsetSize;
    }

    /**
     * Sets size of subsets to be checked during robust estimation.
     * This has to be at least {@link #MINIMUM_MEASUREMENTS_COMMON_Z_AXIS}.
     *
     * @param preliminarySubsetSize size of subsets to be checked during robust estimation.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided value is less than {@link #MINIMUM_MEASUREMENTS_COMMON_Z_AXIS}.
     */
    public void setPreliminarySubsetSize(final int preliminarySubsetSize) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (preliminarySubsetSize < MINIMUM_MEASUREMENTS_COMMON_Z_AXIS) {
            throw new IllegalArgumentException();
        }

        this.preliminarySubsetSize = preliminarySubsetSize;
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    public abstract RobustEstimatorMethod getMethod();

    /**
     * Creates a robust magnetometer calibrator.
     *
     * @param method robust estimator method.
     * @return a robust magnetometer calibrator.
     */
    public static RobustKnownHardIronMagneticFluxDensityNormMagnetometerCalibrator create(

}

    /**
     * Gets known x-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known x-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronX() {
        return hardIronX;
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronX known x-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final double hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
    }

    /**
     * Gets known y-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known y-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronY() {
        return hardIronY;
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @param hardIronY known y-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final double hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = hardIronY;
    }

    /**
     * Gets known z-coordinate of magnetometer hard-iron bias.
     * This is expressed in Teslas (T).
     *
     * @return known z-coordinate of magnetometer hard-iron bias.
     */
    @Override
    public double getHardIronZ() {
        return hardIronZ;
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron bias.
     * This is expressed in meters Teslas (T).
     *
     * @param hardIronZ known z-coordinate of magnetometer
     *                  hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = hardIronZ;
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @return x coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronXAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronX, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known x coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronXAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronX);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known x-coordinate of magnetometer hard-iron.
     *
     * @param hardIronX known x-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronX(final MagneticFluxDensity hardIronX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @return y coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronYAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronY, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known y coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronYAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronY);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known y-coordinate of magnetometer hard-iron.
     *
     * @param hardIronY known y-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronY(final MagneticFluxDensity hardIronY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @return z coordinate of magnetometer hard-iron.
     */
    @Override
    public MagneticFluxDensity getHardIronZAsMagneticFluxDensity() {
        return new MagneticFluxDensity(hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Gets known z coordinate of magnetometer hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronZAsMagneticFluxDensity(final MagneticFluxDensity result) {
        result.setValue(hardIronZ);
        result.setUnit(MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known z-coordinate of magnetometer hard-iron.
     *
     * @param hardIronZ known z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronZ(final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Sets known hard-iron bias coordinates of magnetometer expressed in
     * Teslas (T).
     *
     * @param hardIronX x-coordinate of magnetometer
     *                  known hard-iron bias.
     * @param hardIronY y-coordinate of magnetometer
     *                  known hard-iron bias.
     * @param hardIronZ z-coordinate of magnetometer
     *                  known hard-iron bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final double hardIronX, final double hardIronY, final double hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = hardIronX;
        this.hardIronY = hardIronY;
        this.hardIronZ = hardIronZ;
    }

    /**
     * Sets known hard-iron coordinates.
     *
     * @param hardIronX x-coordinate of magnetometer hard-iron.
     * @param hardIronY y-coordinate of magnetometer hard-iron.
     * @param hardIronZ z-coordinate of magnetometer hard-iron.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIronCoordinates(
            final MagneticFluxDensity hardIronX, final MagneticFluxDensity hardIronY,
            final MagneticFluxDensity hardIronZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.hardIronX = convertMagneticFluxDensity(hardIronX);
        this.hardIronY = convertMagneticFluxDensity(hardIronY);
        this.hardIronZ = convertMagneticFluxDensity(hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @return known hard-iron.
     */
    @Override
    public MagneticFluxDensityTriad getHardIronAsTriad() {
        return new MagneticFluxDensityTriad(MagneticFluxDensityUnit.TESLA, hardIronX, hardIronY, hardIronZ);
    }

    /**
     * Gets known hard-iron.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getHardIronAsTriad(final MagneticFluxDensityTriad result) {
        result.setValueCoordinatesAndUnit(hardIronX, hardIronY, hardIronZ, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Sets known hard-iron.
     *
     * @param hardIron hard-iron to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setHardIron(final MagneticFluxDensityTriad hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        hardIronX = convertMagneticFluxDensity(hardIron.getValueX(), hardIron.getUnit());
        hardIronY = convertMagneticFluxDensity(hardIron.getValueY(), hardIron.getUnit());
        hardIronZ = convertMagneticFluxDensity(hardIron.getValueZ(), hardIron.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {

if (estimatedMm == null) {
            estimatedMm = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
        } else {
            estimatedMm.initialize(0.0);
        }

        estimatedMm.setElementAt(0, 0, sx);
        estimatedMm.setElementAt(1, 0, myx);
        estimatedMm.setElementAt(2, 0, mzx);

        estimatedMm.setElementAt(0, 1, mxy);
        estimatedMm.setElementAt(1, 1, sy);
        estimatedMm.setElementAt(2, 1, mzy);

        estimatedMm.setElementAt(0, 2, mxz);
        estimatedMm.setElementAt(1, 2, myz);
        estimatedMm.setElementAt(2, 2, sz);

        estimatedCovariance = fitter.getCovar();
        estimatedChiSq = fitter.getChisq();
        estimatedMse = fitter.getMse();
    }

    /**
     * Sets input data into Levenberg-Marquardt fitter.
     *
     * @throws WrongSizeException never happens.
     * @throws IOException        if world magnetic model cannot be loaded.
     */
    private void setInputData() throws WrongSizeException, IOException {
        // set input data using:
        // mBmeasx = bx + mBtruex + sx * mBtruex + mxy * mBtruey + mxz * mBtruez
        // mBmeasy = by + myx * mBtruex + mBtruey + sy * mBtruey + myz * mBtruez
        // mBmeasz = bz + mzx * mBtruex + mzy * mBtruey + mBtruez + sz * mBtruez

        final WMMEarthMagneticFluxDensityEstimator wmmEstimator;
        if (magneticModel != null) {
            wmmEstimator = new WMMEarthMagneticFluxDensityEstimator(magneticModel);
        } else {
            wmmEstimator = new WMMEarthMagneticFluxDensityEstimator();
        }

        final var expectedMagneticFluxDensity = new BodyMagneticFluxDensity();
        final var nedFrame = new NEDFrame();
        final var earthB = new NEDMagneticFluxDensity();
        final var cbn = new CoordinateTransformation(FrameType.BODY_FRAME, FrameType.LOCAL_NAVIGATION_FRAME);
        final var cnb = new CoordinateTransformation(FrameType.LOCAL_NAVIGATION_FRAME, FrameType.BODY_FRAME);

        final var numMeasurements = measurements.size();
        final var x = new Matrix(numMeasurements, BodyMagneticFluxDensity.COMPONENTS);
        final var y = new Matrix(numMeasurements, BodyMagneticFluxDensity.COMPONENTS);
        final var specificForceStandardDeviations = new double[numMeasurements];
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredMagneticFluxDensity = measurement.getMagneticFluxDensity();

            // estimate Earth magnetic flux density at frame position and
            // timestamp using WMM
            final var ecefFrame = measurement.getFrame();
            ECEFtoNEDFrameConverter.convertECEFtoNED(ecefFrame, nedFrame);

            final var year = measurement.getYear();

            final var latitude = nedFrame.getLatitude();
            final var longitude = nedFrame.getLongitude();
            final var height = nedFrame.getHeight();

            nedFrame.getCoordinateTransformation(cbn);
            cbn.inverse(cnb);

            wmmEstimator.estimate(latitude, longitude, height, year, earthB);

            // estimate expected body magnetic flux density taking into
            // account body attitude (inverse of frame orientation) and
            // estimated Earth magnetic flux density
            BodyMagneticFluxDensityEstimator.estimate(earthB, cnb, expectedMagneticFluxDensity);

            final var bMeasX = measuredMagneticFluxDensity.getBx();
            final var bMeasY = measuredMagneticFluxDensity.getBy();
            final var bMeasZ = measuredMagneticFluxDensity.getBz();

            final var bTrueX = expectedMagneticFluxDensity.getBx();
            final var bTrueY = expectedMagneticFluxDensity.getBy();
            final var bTrueZ = expectedMagneticFluxDensity.getBz();

            x.setElementAt(i, 0, bTrueX);
            x.setElementAt(i, 1, bTrueY);
            x.setElementAt(i, 2, bTrueZ);

            y.setElementAt(i, 0, bMeasX);
            y.setElementAt(i, 1, bMeasY);
            y.setElementAt(i, 2, bMeasZ);

            specificForceStandardDeviations[i] = measurement.getMagneticFluxDensityStandardDeviation();
            i++;
        }

        fitter.setInputData(x, y, specificForceStandardDeviations);
    }

    /**
     * Converts magnetic flux density value and unit to Teslas.
     *
     * @param value magnetic flux density value.
     * @param unit  unit of magnetic flux density value.
     * @return converted value.
     */
    private static double convertMagneticFluxDensity(final double value, final MagneticFluxDensityUnit unit) {
        return MagneticFluxDensityConverter.convert(value, unit, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Converts magnetic flux density instance to Teslas.
     *
     * @param magneticFluxDensity magnetic flux density instance to be converted.
     * @return converted value.
     */
    private static double convertMagneticFluxDensity(final MagneticFluxDensity magneticFluxDensity) {
        return convertMagneticFluxDensity(magneticFluxDensity.getValue().doubleValue(), magneticFluxDensity.getUnit());
    }
}

}

    /**
     * Gets known x coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @return x coordinate of gyroscope bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets known x coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @param biasX x coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets known y coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @return y coordinate of gyroscope bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets known y coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @param biasY y coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = biasY;
    }

    /**
     * Gets known z coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @return z coordinate of gyroscope bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets known z coordinate of gyroscope bias expressed in radians per second
     * (rad/s).
     *
     * @param biasZ z coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = biasZ;
    }

    /**
     * Gets known x coordinate of gyroscope bias.
     *
     * @return x coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedX() {
        return new AngularSpeed(biasX, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets known x coordinate of gyroscope bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedX(final AngularSpeed result) {
        result.setValue(biasX);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known x coordinate of gyroscope bias.
     *
     * @param biasX x coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final AngularSpeed biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasX = convertAngularSpeed(biasX);
    }

    /**
     * Gets known y coordinate of gyroscope bias.
     *
     * @return y coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedY() {
        return new AngularSpeed(biasY, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets known y coordinate of gyroscope bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedY(final AngularSpeed result) {
        result.setValue(biasY);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known y coordinate of gyroscope bias.
     *
     * @param biasY y coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final AngularSpeed biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasY = convertAngularSpeed(biasY);
    }

    /**
     * Gets known z coordinate of gyroscope bias.
     *
     * @return z coordinate of gyroscope bias.
     */
    @Override
    public AngularSpeed getBiasAngularSpeedZ() {
        return new AngularSpeed(biasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets known z coordinate of gyroscope bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasAngularSpeedZ(final AngularSpeed result) {
        result.setValue(biasZ);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known z coordinate of gyroscope bias.
     *
     * @param biasZ z coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final AngularSpeed biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasZ = convertAngularSpeed(biasZ);
    }

    /**
     * Sets known gyroscope bias coordinates expressed in radians per second
     * (rad/s).
     *
     * @param biasX x coordinate of gyroscope bias.
     * @param biasY y coordinate of gyroscope bias.
     * @param biasZ z coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasX = biasX;
        this.biasY = biasY;
        this.biasZ = biasZ;
    }

    /**
     * Sets known gyroscope bias coordinates.
     *
     * @param biasX x coordinate of gyroscope bias.
     * @param biasY y coordinate of gyroscope bias.
     * @param biasZ z coordinate of gyroscope bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final AngularSpeed biasX, final AngularSpeed biasY, final AngularSpeed biasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.biasX = convertAngularSpeed(biasX);
        this.biasY = convertAngularSpeed(biasY);
        this.biasZ = convertAngularSpeed(biasZ);
    }

    /**
     * Gets known gyroscope bias.
     *
     * @return known gyroscope bias.
     */
    public AngularSpeedTriad getBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known gyroscope bias.
     *
     * @param result instance where result will be stored.
     */
    public void getBiasAsTriad(final AngularSpeedTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets known gyroscope bias.
     *
     * @param bias gyroscope bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setBias(final AngularSpeedTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAngularSpeed(bias.getValueX(), bias.getUnit());
        biasY = convertAngularSpeed(bias.getValueY(), bias.getUnit());
        biasZ = convertAngularSpeed(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets known gyroscope bias as an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @return array containing coordinate of known bias.
     */
    @Override
    public double[] getBias() {

biasZ = convertAcceleration(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {

}

    /**
     * Gets initial x scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {

initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @return collection of sequences of timestamped body kinematics
     * measurements.
     */
    @Override
    public List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> getSequences() {
        return sequences;
    }

    /**
     * Sets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @param sequences collection of sequences of timestamped body
     *                  kinematics measurements.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setSequences(
            final List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> sequences) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.sequences = sequences;
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.BODY_KINEMATICS_SEQUENCE;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return true;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement/sequence or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return false;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Indicates whether G-dependent cross biases are being estimated
     * or not.
     * When enabled, this adds 9 variables from Gg matrix.
     *
     * @return true if G-dependent cross biases will be estimated,
     * false otherwise.
     */
    public boolean isGDependentCrossBiasesEstimated() {
        return estimateGDependentCrossBiases;
    }

    /**
     * Specifies whether G-dependent cross biases are being estimated
     * or not.
     * When enabled, this adds 9 variables from Gg matrix.
     *
     * @param estimateGDependentCrossBiases true if G-dependent cross
     *                                      biases will be estimated,
     *                                      false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setGDependentCrossBiasesEstimated(final boolean estimateGDependentCrossBiases) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.estimateGDependentCrossBiases = estimateGDependentCrossBiases;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    public EasyGyroscopeCalibratorListener getListener() {

}

    /**
     * Gets initial x scaling factor.
     *
     * @return initial x scaling factor.
     */
    @Override
    public double getInitialSx() {
        return initialSx;
    }

    /**
     * Sets initial x scaling factor.
     *
     * @param initialSx initial x scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSx(final double initialSx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
    }

    /**
     * Gets initial y scaling factor.
     *
     * @return initial y scaling factor.
     */
    @Override
    public double getInitialSy() {
        return initialSy;
    }

    /**
     * Sets initial y scaling factor.
     *
     * @param initialSy initial y scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSy(final double initialSy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSy = initialSy;
    }

    /**
     * Gets initial z scaling factor.
     *
     * @return initial z scaling factor.
     */
    @Override
    public double getInitialSz() {
        return initialSz;
    }

    /**
     * Sets initial z scaling factor.
     *
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialSz(final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSz = initialSz;
    }

    /**
     * Gets initial x-y cross coupling error.
     *
     * @return initial x-y cross coupling error.
     */
    @Override
    public double getInitialMxy() {
        return initialMxy;
    }

    /**
     * Sets initial x-y cross coupling error.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxy(final double initialMxy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
    }

    /**
     * Gets initial x-z cross coupling error.
     *
     * @return initial x-z cross coupling error.
     */
    @Override
    public double getInitialMxz() {
        return initialMxz;
    }

    /**
     * Sets initial x-z cross coupling error.
     *
     * @param initialMxz initial x-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMxz(final double initialMxz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxz = initialMxz;
    }

    /**
     * Gets initial y-x cross coupling error.
     *
     * @return initial y-x cross coupling error.
     */
    @Override
    public double getInitialMyx() {
        return initialMyx;
    }

    /**
     * Sets initial y-x cross coupling error.
     *
     * @param initialMyx initial y-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyx(final double initialMyx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyx = initialMyx;
    }

    /**
     * Gets initial y-z cross coupling error.
     *
     * @return initial y-z cross coupling error.
     */
    @Override
    public double getInitialMyz() {
        return initialMyz;
    }

    /**
     * Sets initial y-z cross coupling error.
     *
     * @param initialMyz initial y-z cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMyz(final double initialMyz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMyz = initialMyz;
    }

    /**
     * Gets initial z-x cross coupling error.
     *
     * @return initial z-x cross coupling error.
     */
    @Override
    public double getInitialMzx() {
        return initialMzx;
    }

    /**
     * Sets initial z-x cross coupling error.
     *
     * @param initialMzx initial z-x cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzx(final double initialMzx) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzx = initialMzx;
    }

    /**
     * Gets initial z-y cross coupling error.
     *
     * @return initial z-y cross coupling error.
     */
    @Override
    public double getInitialMzy() {
        return initialMzy;
    }

    /**
     * Sets initial z-y cross coupling error.
     *
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialMzy(final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors.
     *
     * @param initialSx initial x scaling factor.
     * @param initialSy initial y scaling factor.
     * @param initialSz initial z scaling factor.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactors(
            final double initialSx, final double initialSy, final double initialSz) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialSx = initialSx;
        this.initialSy = initialSy;
        this.initialSz = initialSz;
    }

    /**
     * Sets initial cross coupling errors.
     *
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialCrossCouplingErrors(
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialMxy = initialMxy;
        this.initialMxz = initialMxz;
        this.initialMyx = initialMyx;
        this.initialMyz = initialMyz;
        this.initialMzx = initialMzx;
        this.initialMzy = initialMzy;
    }

    /**
     * Sets initial scaling factors and cross coupling errors.
     *
     * @param initialSx  initial x scaling factor.
     * @param initialSy  initial y scaling factor.
     * @param initialSz  initial z scaling factor.
     * @param initialMxy initial x-y cross coupling error.
     * @param initialMxz initial x-z cross coupling error.
     * @param initialMyx initial y-x cross coupling error.
     * @param initialMyz initial y-z cross coupling error.
     * @param initialMzx initial z-x cross coupling error.
     * @param initialMzy initial z-y cross coupling error.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialScalingFactorsAndCrossCouplingErrors(
            final double initialSx, final double initialSy, final double initialSz,
            final double initialMxy, final double initialMxz, final double initialMyx,
            final double initialMyz, final double initialMzx, final double initialMzy) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        setInitialScalingFactors(initialSx, initialSy, initialSz);
        setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {

initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {

        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @return collection of sequences of timestamped body kinematics
     * measurements.
     */
    @Override
    public List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> getSequences() {
        return sequences;
    }

    /**
     * Sets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @param sequences collection of sequences of timestamped body
     *                  kinematics measurements.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setSequences(
            final List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> sequences) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.sequences = sequences;
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.BODY_KINEMATICS_SEQUENCE;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return true;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Indicates whether G-dependent cross biases are being estimated
     * or not.
     * When enabled, this adds 9 variables from Gg matrix.
     *
     * @return true if G-dependent cross biases will be estimated,
     * false otherwise.
     */
    public boolean isGDependentCrossBiasesEstimated() {
        return estimateGDependentCrossBiases;
    }

    /**
     * Specifies whether G-dependent cross biases are being estimated
     * or not.
     * When enabled, this adds 9 variables from Gg matrix.
     *
     * @param estimateGDependentCrossBiases true if G-dependent cross
     *                                      biases will be estimated,
     *                                      false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setGDependentCrossBiasesEstimated(final boolean estimateGDependentCrossBiases) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.estimateGDependentCrossBiases = estimateGDependentCrossBiases;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    public RobustEasyGyroscopeCalibratorListener getListener() {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * ECEF coordinates.
     *
     * @return position where body kinematics measures have been taken.
     */
    public ECEFPosition getEcefPosition() {
        return position;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * ECEF coordinates.
     *
     * @param position position where body kinematics measures have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final ECEFPosition position) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.position = position;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @return position where body kinematics measures have been taken or null if
     * not available.
     */
    public NEDPosition getNedPosition() {
        final var result = new NEDPosition();
        return getNedPosition(result) ? result : null;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if NED position could be computed, false otherwise.
     */
    public boolean getNedPosition(final NEDPosition result) {

        if (position != null) {
            final var velocity = new NEDVelocity();
            ECEFtoNEDPositionVelocityConverter.convertECEFtoNED(position.getX(), position.getY(), position.getZ(),
                    0.0, 0.0, 0.0, result, velocity);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Sets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @param position position where body kinematics measures have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final NEDPosition position) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.position = convertPosition(position);
    }

    /**
     * Gets a list of body kinematics measurements taken at a
     * given position with different unknown orientations and containing the
     * standard deviations of accelerometer and gyroscope measurements.
     *
     * @return list of body kinematics measurements.
     */
    @Override
    public List<StandardDeviationBodyKinematics> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a list of body kinematics measurements taken at a
     * given position with different unknown orientations and containing the
     * standard deviations of accelerometer and gyroscope measurements.
     *
     * @param measurements list of body kinematics measurements.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final List<StandardDeviationBodyKinematics> measurements) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public AccelerometerCalibratorMeasurementType getMeasurementType() {
        return AccelerometerCalibratorMeasurementType.STANDARD_DEVIATION_BODY_KINEMATICS;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return true;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    public RobustKnownBiasAndPositionAccelerometerCalibratorListener getListener() {

setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public Collection<StandardDeviationFrameBodyKinematics> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate the a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @param measurements collection of body kinematics measurements taken at different
     *                     frames (positions, orientations and velocities).
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(
            final Collection<? extends StandardDeviationFrameBodyKinematics> measurements) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        //noinspection unchecked
        this.measurements = (Collection<StandardDeviationFrameBodyKinematics>) measurements;
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.STANDARD_DEVIATION_FRAME_BODY_KINEMATICS_MEASUREMENT;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return false;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement/sequence or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return false;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Mg matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Mg matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this calibrator.
     *
     * @return listener to handle events raised by this calibrator.
     */
    @Override
    public KnownBiasAndFrameGyroscopeNonLinearLeastSquaresCalibratorListener getListener() {

this(measurements, commonAxisUsed, initialBias, initialMa);
        this.listener = listener;
    }

    /**
     * Gets initial x-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return initial x-coordinate of accelerometer bias.
     */
    @Override
    public double getInitialBiasX() {
        return initialBiasX;
    }

    /**
     * Sets initial x-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasX(final double initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
    }

    /**
     * Gets initial y-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return initial y-coordinate of accelerometer bias.
     */
    @Override
    public double getInitialBiasY() {
        return initialBiasY;
    }

    /**
     * Sets initial y-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasY(final double initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = initialBiasY;
    }

    /**
     * Gets initial z-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return initial z-coordinate of accelerometer bias.
     */
    @Override
    public double getInitialBiasZ() {
        return initialBiasZ;
    }

    /**
     * Sets initial z-coordinate of accelerometer bias to be used to find a solution.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasZ(final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Gets initial x-coordinate of accelerometer bias to be used to find a solution.
     *
     * @return initial x-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getInitialBiasXAsAcceleration() {
        return new Acceleration(initialBiasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial x-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasXAsAcceleration(final Acceleration result) {
        result.setValue(initialBiasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial x-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasX(final Acceleration initialBiasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAcceleration(initialBiasX);
    }

    /**
     * Gets initial y-coordinate of accelerometer bias to be used to find a solution.
     *
     * @return initial y-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getInitialBiasYAsAcceleration() {
        return new Acceleration(initialBiasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial y-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasYAsAcceleration(final Acceleration result) {
        result.setValue(initialBiasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial y-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasY(final Acceleration initialBiasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasY = convertAcceleration(initialBiasY);
    }

    /**
     * Gets initial z-coordinate of accelerometer bias to be used to find a solution.
     *
     * @return initial z-coordinate of accelerometer bias.
     */
    @Override
    public Acceleration getInitialBiasZAsAcceleration() {
        return new Acceleration(initialBiasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial z-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getInitialBiasZAsAcceleration(final Acceleration result) {
        result.setValue(initialBiasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial z-coordinate of accelerometer bias to be used to find a solution.
     *
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBiasZ(final Acceleration initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasZ = convertAcceleration(initialBiasZ);
    }

    /**
     * Sets initial bias coordinates of accelerometer used to find a solution
     * expressed in meters per squared second (m/s^2).
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(
            final double initialBiasX, final double initialBiasY, final double initialBiasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = initialBiasX;
        this.initialBiasY = initialBiasY;
        this.initialBiasZ = initialBiasZ;
    }

    /**
     * Sets initial bias coordinates of accelerometer used to find a solution.
     *
     * @param initialBiasX initial x-coordinate of accelerometer bias.
     * @param initialBiasY initial y-coordinate of accelerometer bias.
     * @param initialBiasZ initial z-coordinate of accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(
            final Acceleration initialBiasX, final Acceleration initialBiasY, final Acceleration initialBiasZ)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.initialBiasX = convertAcceleration(initialBiasX);
        this.initialBiasY = convertAcceleration(initialBiasY);
        this.initialBiasZ = convertAcceleration(initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of accelerometer used to find a solution.
     *
     * @return initial bias coordinates.
     */
    @Override
    public AccelerationTriad getInitialBiasAsTriad() {
        return new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND,
                initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of accelerometer used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getInitialBiasAsTriad(final AccelerationTriad result) {
        result.setValueCoordinatesAndUnit(initialBiasX, initialBiasY, initialBiasZ,
                AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial bias coordinates of accelerometer used to find a solution.
     *
     * @param initialBias initial bias coordinates to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setInitialBias(final AccelerationTriad initialBias) throws LockedException {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets ground truth gravity norm to be expected at location where measurements have been made,
     * expressed in meter per squared second (m/s^2).
     *
     * @return ground truth gravity norm or null.
     */
    public Double getGroundTruthGravityNorm() {
        return groundTruthGravityNorm;
    }

    /**
     * Sets ground truth gravity norm to be expected at location where
     * measurements have been made, expressed in meters per squared second
     * (m/s^2).
     *
     * @param groundTruthGravityNorm ground truth gravity norm or
     *                               null if undefined.
     * @throws IllegalArgumentException if provided value is negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setGroundTruthGravityNorm(final Double groundTruthGravityNorm) throws LockedException {
        if (isRunning()) {
            throw new LockedException();
        }
        internalSetGroundTruthGravityNorm(groundTruthGravityNorm);
    }

    /**
     * Gets ground truth gravity norm to be expected at location where measurements have been made.
     *
     * @return ground truth gravity norm or null.
     */
    public Acceleration getGroundTruthGravityNormAsAcceleration() {
        return groundTruthGravityNorm != null
                ? new Acceleration(groundTruthGravityNorm, AccelerationUnit.METERS_PER_SQUARED_SECOND) : null;
    }

    /**
     * Gets ground truth gravity norm to be expected at location where measurements have been made.
     *
     * @param result instance where result will be stored.
     * @return true if ground truth gravity norm has been defined, false if it is not available yet.
     */
    public boolean getGroundTruthGravityNormAsAcceleration(final Acceleration result) {
        if (groundTruthGravityNorm != null) {
            result.setValue(groundTruthGravityNorm);
            result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Sets ground truth gravity norm to be expected at location where
     * measurements have been made.
     *
     * @param groundTruthGravityNorm ground truth gravity norm or null
     *                               if undefined.
     * @throws IllegalArgumentException if provided value is negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setGroundTruthGravityNorm(final Acceleration groundTruthGravityNorm) throws LockedException {
        setGroundTruthGravityNorm(groundTruthGravityNorm != null ? convertAcceleration(groundTruthGravityNorm) : null);
    }

    /**
     * Gets a list of body kinematics measurements taken at a
     * given position with different unknown orientations and containing the
     * standard deviations of accelerometer and gyroscope measurements.
     *
     * @return list of body kinematics measurements.
     */
    @Override
    public List<StandardDeviationBodyKinematics> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a list of body kinematics measurements taken at a
     * given position with different unknown orientations and containing the
     * standard deviations of accelerometer and gyroscope measurements.
     *
     * @param measurements list of body kinematics measurements.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final List<StandardDeviationBodyKinematics> measurements) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public AccelerometerCalibratorMeasurementType getMeasurementType() {
        return AccelerometerCalibratorMeasurementType.STANDARD_DEVIATION_BODY_KINEMATICS;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return true;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    public RobustKnownBiasAndGravityNormAccelerometerCalibratorListener getListener() {

return false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed
     * for the accelerometer, gyroscope and magnetometer.
     *
     * @throws AlgebraException if there are numerical errors.
     * @throws IOException      if world magnetic model cannot be loaded.
     */
    private void calibrateCommonAxis() throws AlgebraException, IOException {
        // The magnetometer model is:
        // mBmeas = bm + (I + Mm) * mBtrue + w

        // Ideally a least squares solution tries to minimize noise component, so:
        // mBmeas = bm + (I + Mm) * mBtrue

        // Hence:
        // [mBmeasx] = [bx] + ( [1  0   0] + [sx    mxy mxz])   [mBtruex]
        // [mBmeasy] = [by]     [0  1   0]   [myx   sy  myz]    [mBtruey]
        // [mBmeasz] = [bz]     [0  0   1]   [mzx   mzy sz ]    [mBtruez]

        // where myx = mzx = mzy = 0

        // Hence:
        // [mBmeasx] = [bx] + ( [1  0   0] + [sx    mxy mxz])   [mBtruex]
        // [mBmeasy] = [by]     [0  1   0]   [0     sy  myz]    [mBtruey]
        // [mBmeasz] = [bz]     [0  0   1]   [0     0   sz ]    [mBtruez]

        // [mBmeasx] = [bx] +   [1+sx   mxy     mxz ][mBtruex]
        // [mBmeasy]   [by]     [0      1+sy    myz ][mBtruey]
        // [mBmeasz]   [bz]     [0      0       1+sz][mBtruez]

        // mBmeasx = bx + (1+sx) * mBtruex + mxy * mBtruey + mxz * mBtruez
        // mBmeasy = by + (1+sy) * mBtruey + myz * mBtruez
        // mBmeasz = bz + (1+sz) * mBtruez

        // Where the unknowns are: bx, by, bz, sx, sy, sz, mxy mxz, myz
        // Reordering:
        // mBmeasx = bx + mBtruex + sx * mBtruex + mxy * mBtruey + mxz * mBtruez
        // mBmeasy = by + mBtruey + sy * mBtruey + myz * mBtruez
        // mBmeasz = bz + mBtruez + sz * mBtruez

        // mBmeasx - mBtruex = bx + sx * mBtruex + mxy * mBtruey + mxz * mBtruez
        // mBmeasy - mBtruey = by + sy * mBtruey + myz * mBtruez
        // mBmeasz - mBtruez = bz + sz * mBtruez

        // [1   0   0   mBtruex  0        0        mBtruey  mBtruez  0      ][bx ] = [mBmeasx - mBtruex]
        // [0   1   0   0        mBtruey  0        0        0        mBtruez][by ]   [mBmeasy - mBtruey]
        // [0   0   1   0        0        mBtruez  0        0        0      ][bz ]   [mBmeasz - mBtruez]
        //                                                                   [sx ]
        //                                                                   [sy ]
        //                                                                   [sz ]
        //                                                                   [mxy]
        //                                                                   [mxz]
        //                                                                   [myz]

        final WMMEarthMagneticFluxDensityEstimator wmmEstimator;
        if (magneticModel != null) {
            wmmEstimator = new WMMEarthMagneticFluxDensityEstimator(magneticModel);
        } else {
            wmmEstimator = new WMMEarthMagneticFluxDensityEstimator();
        }

        final var expectedMagneticFluxDensity = new BodyMagneticFluxDensity();
        final var nedFrame = new NEDFrame();
        final var earthB = new NEDMagneticFluxDensity();
        final var cbn = new CoordinateTransformation(FrameType.BODY_FRAME, FrameType.LOCAL_NAVIGATION_FRAME);
        final var cnb = new CoordinateTransformation(FrameType.LOCAL_NAVIGATION_FRAME, FrameType.BODY_FRAME);

        final var rows = EQUATIONS_PER_MEASUREMENT * measurements.size();
        final var a = new Matrix(rows, COMMON_Z_AXIS_UNKNOWNS);
        final var b = new Matrix(rows, 1);
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredMagneticFluxDensity = measurement.getMagneticFluxDensity();

            // estimate Earth magnetic flux density at frame position and
            // timestamp using WMM
            final var ecefFrame = measurement.getFrame();
            ECEFtoNEDFrameConverter.convertECEFtoNED(ecefFrame, nedFrame);

            final var year = measurement.getYear();

            final var latitude = nedFrame.getLatitude();
            final var longitude = nedFrame.getLongitude();
            final var height = nedFrame.getHeight();

            nedFrame.getCoordinateTransformation(cbn);
            cbn.inverse(cnb);

            wmmEstimator.estimate(latitude, longitude, height, year, earthB);

            // estimate expected body magnetic flux density taking into
            // account body attitude (inverse of frame orientation) and
            // estimated Earth magnetic flux density
            BodyMagneticFluxDensityEstimator.estimate(earthB, cnb, expectedMagneticFluxDensity);

            final var bMeasX = measuredMagneticFluxDensity.getBx();
            final var bMeasY = measuredMagneticFluxDensity.getBy();
            final var bMeasZ = measuredMagneticFluxDensity.getBz();

            final var bTrueX = expectedMagneticFluxDensity.getBx();
            final var bTrueY = expectedMagneticFluxDensity.getBy();
            final var bTrueZ = expectedMagneticFluxDensity.getBz();

            a.setElementAt(i, 0, 1.0);

public INSLooselyCoupledKalmanInitializerConfig(final INSLooselyCoupledKalmanInitializerConfig input) {
        copyFrom(input);
    }

    /**
     * Gets initial attitude uncertainty per axis expressed in radians (rad).
     *
     * @return initial attitude uncertainty per axis expressed in radians (rad).
     */
    public double getInitialAttitudeUncertainty() {
        return initialAttitudeUncertainty;
    }

    /**
     * Sets initial attitude uncertainty per axis expressed in radians (rad).
     *
     * @param initialAttitudeUncertainty initial attitude uncertainty per axis expressed
     *                                   in radians (rad).
     */
    public void setInitialAttitudeUncertainty(final double initialAttitudeUncertainty) {
        this.initialAttitudeUncertainty = initialAttitudeUncertainty;
    }

    /**
     * Gets initial attitude uncertainty per axis.
     *
     * @param result instance where initial attitude uncertainty per axis will be stored.
     */
    public void getInitialAttitudeUncertaintyAngle(final Angle result) {
        result.setValue(initialAttitudeUncertainty);
        result.setUnit(AngleUnit.RADIANS);
    }

    /**
     * Gets initial attitude uncertainty per axis.
     *
     * @return initial attitude uncertainty per axis.
     */
    public Angle getInitialAttitudeUncertaintyAngle() {
        return new Angle(initialAttitudeUncertainty, AngleUnit.RADIANS);
    }

    /**
     * Sets initial attitude uncertainty per axis.
     *
     * @param initialAttitudeUncertainty initial attitude uncertainty per axis.
     */
    public void setInitialAttitudeUncertainty(final Angle initialAttitudeUncertainty) {
        this.initialAttitudeUncertainty = AngleConverter.convert(initialAttitudeUncertainty.getValue().doubleValue(),
                initialAttitudeUncertainty.getUnit(), AngleUnit.RADIANS);
    }

    /**
     * Gets initial velocity uncertainty per axis expressed in meters per second (m/s).
     *
     * @return initial velocity uncertainty per axis expressed in meters per second (m/s).
     */
    public double getInitialVelocityUncertainty() {
        return initialVelocityUncertainty;
    }

    /**
     * Sets initial velocity uncertainty per axis expressed in meters per second (m/s).
     *
     * @param initialVelocityUncertainty initial velocity uncertainty per axis expressed
     *                                   in meters per second (m/s).
     */
    public void setInitialVelocityUncertainty(final double initialVelocityUncertainty) {
        this.initialVelocityUncertainty = initialVelocityUncertainty;
    }

    /**
     * Gets initial velocity uncertainty per axis.
     *
     * @param result instance where initial attitude uncertainty per axis will be stored.
     */
    public void getInitialVelocityUncertaintySpeed(final Speed result) {
        result.setValue(initialVelocityUncertainty);
        result.setUnit(SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Gets initial velocity uncertainty per axis.
     *
     * @return initial velocity uncertainty per axis.
     */
    public Speed getInitialVelocityUncertaintySpeed() {
        return new Speed(initialVelocityUncertainty, SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Sets initial velocity uncertainty per axis.
     *
     * @param initialVelocityUncertainty initial velocity uncertainty per axis.
     */
    public void setInitialVelocityUncertainty(final Speed initialVelocityUncertainty) {
        this.initialVelocityUncertainty = SpeedConverter.convert(initialVelocityUncertainty.getValue().doubleValue(),
                initialVelocityUncertainty.getUnit(), SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Gets initial position uncertainty per axis expressed in meters (m)
     *
     * @return initial position uncertainty per axis expressed in meters (m).
     */
    public double getInitialPositionUncertainty() {
        return initialPositionUncertainty;
    }

    /**
     * Sets initial position uncertainty per axis expressed in meters (m)
     *
     * @param initialPositionUncertainty initial position uncertainty per axis expressed
     *                                   in meters (m).
     */
    public void setInitialPositionUncertainty(final double initialPositionUncertainty) {
        this.initialPositionUncertainty = initialPositionUncertainty;
    }

    /**
     * Gets initial position uncertainty per axis.
     *
     * @param result instance where initial position uncertainty per axis will be stored.
     */
    public void getInitialPositionUncertaintyDistance(final Distance result) {
        result.setValue(initialPositionUncertainty);
        result.setUnit(DistanceUnit.METER);
    }

    /**
     * Gets initial position uncertainty per axis.
     *
     * @return initial position uncertainty per axis.
     */
    public Distance getInitialPositionUncertaintyDistance() {
        return new Distance(initialPositionUncertainty, DistanceUnit.METER);
    }

    /**
     * Sets initial position uncertainty per axis.
     *
     * @param initialPositionUncertainty initial position uncertainty per axis.
     */
    public void setInitialPositionUncertainty(final Distance initialPositionUncertainty) {
        this.initialPositionUncertainty = DistanceConverter.convert(initialPositionUncertainty.getValue().doubleValue(),
                initialPositionUncertainty.getUnit(), DistanceUnit.METER);
    }

    /**
     * Gets initial acceleration bias uncertainty expressed in meters per squared second (m/s^2).
     *
     * @return initial acceleration bias uncertainty expressed in meters per squared second (m/s^2).
     */
    public double getInitialAccelerationBiasUncertainty() {
        return initialAccelerationBiasUncertainty;
    }

    /**
     * Sets initial acceleration bias uncertainty expressed in meters per squared second (m/s^2).
     *
     * @param initialAccelerationBiasUncertainty initial acceleration bias uncertainty expressed in
     *                                           meters per squared second (m/s^2).
     */
    public void setInitialAccelerationBiasUncertainty(final double initialAccelerationBiasUncertainty) {
        this.initialAccelerationBiasUncertainty = initialAccelerationBiasUncertainty;
    }

    /**
     * Gets initial acceleration bias uncertainty.
     *
     * @param result instance where initial acceleration bias uncertainty will be stored.
     */
    public void getInitialAccelerationBiasUncertaintyAcceleration(final Acceleration result) {
        result.setValue(initialAccelerationBiasUncertainty);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial acceleration bias uncertainty.
     *
     * @return initial acceleration bias uncertainty.
     */
    public Acceleration getInitialAccelerationBiasUncertaintyAcceleration() {
        return new Acceleration(initialAccelerationBiasUncertainty, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets initial acceleration bias uncertainty.
     *
     * @param initialAccelerationUncertainty initial acceleration bias uncertainty.
     */
    public void setInitialAccelerationBiasUncertainty(final Acceleration initialAccelerationUncertainty) {
        initialAccelerationBiasUncertainty = AccelerationConverter.convert(
                initialAccelerationUncertainty.getValue().doubleValue(), initialAccelerationUncertainty.getUnit(),
                AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets initial gyroscope bias uncertainty expressed in radians per second (rad/s).
     *
     * @return initial gyroscope bias uncertainty expressed in radians per second (rad/s).
     */
    public double getInitialGyroscopeBiasUncertainty() {
        return initialGyroscopeBiasUncertainty;
    }

    /**
     * Sets initial gyroscope bias uncertainty expressed in radians per second (rad/s).
     *
     * @param initialGyroscopeBiasUncertainty initial gyroscope bias uncertainty expressed
     *                                        in radians per second (rad/s).
     */
    public void setInitialGyroscopeBiasUncertainty(final double initialGyroscopeBiasUncertainty) {
        this.initialGyroscopeBiasUncertainty = initialGyroscopeBiasUncertainty;
    }

    /**
     * Gets initial gyroscope bias uncertainty.
     *
     * @param result instance where initial gyroscope bias uncertainty will be stored.
     */
    public void getInitialGyroscopeBiasUncertaintyAngularSpeed(final AngularSpeed result) {
        result.setValue(initialGyroscopeBiasUncertainty);
        result.setUnit(AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Gets initial gyroscope bias uncertainty.
     *
     * @return initial gyroscope bias uncertainty.
     */
    public AngularSpeed getInitialGyroscopeBiasUncertaintyAngularSpeed() {
        return new AngularSpeed(initialGyroscopeBiasUncertainty, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets initial gyroscope bias uncertainty.
     *
     * @param initialGyroscopeBiasUncertainty initial gyroscope bias uncertainty.
     */
    public void setInitialGyroscopeBiasUncertainty(final AngularSpeed initialGyroscopeBiasUncertainty) {
        this.initialGyroscopeBiasUncertainty = AngularSpeedConverter.convert(
                initialGyroscopeBiasUncertainty.getValue().doubleValue(), initialGyroscopeBiasUncertainty.getUnit(),
                AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Sets configuration parameters.
     *
     * @param initialAttitudeUncertainty         initial attitude uncertainty per axis
     *                                           expressed in radians (rad).
     * @param initialVelocityUncertainty         initial velocity uncertainty per axis
     *                                           expressed in meters per second (m/s).
     * @param initialPositionUncertainty         initial position uncertainty per axis
     *                                           expressed in meters (m).
     * @param initialAccelerationBiasUncertainty initial acceleration bias uncertainty
     *                                           expressed in meters per squared second (m/s^2).
     * @param initialGyroscopeBiasUncertainty    initial gyroscope bias uncertainty
     *                                           expressed in radians per second (rad/s).
     */
    public void setValues(

setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets a list of body kinematics measurements taken at different
     * frames (positions, orientations and velocities) and containing the standard
     * deviations of accelerometer and gyroscope measurements.
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate the a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public List<StandardDeviationFrameBodyKinematics> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a list of body kinematics measurements taken at different
     * frames (positions, orientations and velocities) and containing the standard
     * deviations of accelerometer and gyroscope measurements.
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate the a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @param measurements collection of body kinematics measurements taken at different
     *                     frames (positions, orientations and velocities).
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final List<StandardDeviationFrameBodyKinematics> measurements) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.STANDARD_DEVIATION_FRAME_BODY_KINEMATICS_MEASUREMENT;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return true;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    public RobustKnownBiasAndFrameGyroscopeCalibratorListener getListener() {

final Time timeInterval, final ECEFFrame frame, final ECEFFrame oldFrame, final BodyKinematics result) {
        estimateKinematics(timeInterval, frame, oldFrame.getCoordinateTransformation(),
                oldFrame.getVx(), oldFrame.getVy(), oldFrame.getVz(), result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static void estimateKinematics(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final Speed vx, final Speed vy, final Speed vz, final Speed oldVx, final Speed oldVy, final Speed oldVz,
            final double x, final double y, final double z, final BodyKinematics result) {
        estimateKinematics(timeInterval, c, oldC,
                SpeedConverter.convert(vx.getValue().doubleValue(), vx.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(vy.getValue().doubleValue(), vy.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(vz.getValue().doubleValue(), vz.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVx.getValue().doubleValue(), oldVx.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVy.getValue().doubleValue(), oldVy.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVz.getValue().doubleValue(), oldVz.getUnit(), SpeedUnit.METERS_PER_SECOND),
                x, y, z, result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs.
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static void estimateKinematics(
            final Time timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final Speed vx, final Speed vy, final Speed vz, final Speed oldVx, final Speed oldVy, final Speed oldVz,
            final double x, final double y, final double z, final BodyKinematics result) {
        estimateKinematics(timeInterval, c, oldC,
                SpeedConverter.convert(vx.getValue().doubleValue(), vx.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(vy.getValue().doubleValue(), vy.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(vz.getValue().doubleValue(), vz.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVx.getValue().doubleValue(), oldVx.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVy.getValue().doubleValue(), oldVy.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVz.getValue().doubleValue(), oldVz.getUnit(), SpeedUnit.METERS_PER_SECOND),
                x, y, z, result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param position     cartesian body position resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static void estimateKinematics(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,

public int getMinimumRequiredMeasurements() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Indicates whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @return indicates whether a linear calibrator is used or not for
     * preliminary solutions.
     */
    public boolean isLinearCalibratorUsed() {
        return useLinearCalibrator;
    }

    /**
     * Specifies whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @param linearCalibratorUsed indicates whether a linear calibrator is used
     *                             or not for preliminary solutions.
     * @throws LockedException if calibrator is currently running.
     */
    public void setLinearCalibratorUsed(final boolean linearCalibratorUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        useLinearCalibrator = linearCalibratorUsed;
    }

    /**
     * Indicates whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @return true if preliminary solutions must be refined after an initial linear solution, false
     * otherwise.
     */
    public boolean isPreliminarySolutionRefined() {
        return refinePreliminarySolutions;
    }

    /**
     * Specifies whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @param preliminarySolutionRefined true if preliminary solutions must be refined after an
     *                                   initial linear solution, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPreliminarySolutionRefined(final boolean preliminarySolutionRefined) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        refinePreliminarySolutions = preliminarySolutionRefined;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return array containing x,y,z components of estimated accelerometer biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where estimated accelerometer biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return column matrix containing x,y,z components of estimated accelerometer
     * biases
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFx() {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @return collection of sequences of timestamped body kinematics
     * measurements.
     */
    @Override
    public List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> getSequences() {
        return sequences;
    }

    /**
     * Sets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @param sequences collection of sequences of timestamped body
     *                  kinematics measurements.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setSequences(final List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> sequences)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.sequences = sequences;
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.BODY_KINEMATICS_SEQUENCE;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return true;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement/sequence or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {

initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @return collection of sequences of timestamped body kinematics
     * measurements.
     */
    @Override
    public List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> getSequences() {
        return sequences;
    }

    /**
     * Sets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @param sequences collection of sequences of timestamped body
     *                  kinematics measurements.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setSequences(
            final List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> sequences) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.sequences = sequences;
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.BODY_KINEMATICS_SEQUENCE;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return true;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement/sequence or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @return collection of sequences of timestamped body kinematics
     * measurements.
     */
    @Override
    public List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> getSequences() {
        return sequences;
    }

    /**
     * Sets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @param sequences collection of sequences of timestamped body
     *                  kinematics measurements.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setSequences(final List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> sequences)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.sequences = sequences;
    }

    /**
     * Indicates the type of measurement or sequence used by this calibrator.
     *
     * @return type of measurement or sequence used by this calibrator.
     */
    @Override
    public GyroscopeCalibratorMeasurementOrSequenceType getMeasurementOrSequenceType() {
        return GyroscopeCalibratorMeasurementOrSequenceType.BODY_KINEMATICS_SEQUENCE;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements or sequences
     * in a list or not.
     *
     * @return true if measurements or sequences must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsOrSequencesRequired() {
        return true;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement/sequence or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {

}

    /**
     * Gets body to ECEF coordinate transformation.
     *
     * @param threshold threshold to determine whether current body to ECEF transformation
     *                  matrix is valid or not (to check that matrix is 3x3 orthonormal).
     * @return body to ECEF coordinate transformation.
     * @throws InvalidRotationMatrixException if current body to ECEF transformation matrix
     *                                        is considered not valid (is not a 3x3 orthonormal matrix) with provided threshold.
     */
    public CoordinateTransformation getC(final double threshold) throws InvalidRotationMatrixException {
        return bodyToEcefCoordinateTransformationMatrix != null
                ? new CoordinateTransformation(bodyToEcefCoordinateTransformationMatrix, FrameType.BODY_FRAME,
                FrameType.EARTH_CENTERED_EARTH_FIXED_FRAME, threshold)
                : null;
    }

    /**
     * Gets body to ECEF coordinate transformation.
     *
     * @param result instance where body to ECEF coordinate transformation will be stored.
     * @return true if result instance was updated, false otherwise.
     * @throws InvalidRotationMatrixException if current body to ECEF transformation matrix
     *                                        is not valid (is not a 3x3 orthonormal matrix).
     */
    public boolean getC(final CoordinateTransformation result) throws InvalidRotationMatrixException {
        if (bodyToEcefCoordinateTransformationMatrix != null) {
            result.setSourceType(FrameType.BODY_FRAME);
            result.setDestinationType(FrameType.EARTH_CENTERED_EARTH_FIXED_FRAME);
            result.setMatrix(bodyToEcefCoordinateTransformationMatrix);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets body to ECEF coordinate transformation.
     *
     * @param result    instance where body to ECEF coordinate transformation will be stored.
     * @param threshold threshold to determine whether current body to ECEF transformation
     *                  matrix is valid or not (to check that matrix is 3x3 orthonormal).
     * @return true if result instance was updated, false otherwise.
     * @throws InvalidRotationMatrixException if current body to ECEF transformation matrix
     *                                        is not valid (is not a 3x3 orthonormal matrix) with provided threshold.
     */
    public boolean getC(final CoordinateTransformation result, final double threshold)
            throws InvalidRotationMatrixException {
        if (bodyToEcefCoordinateTransformationMatrix != null) {
            result.setSourceType(FrameType.BODY_FRAME);
            result.setDestinationType(FrameType.EARTH_CENTERED_EARTH_FIXED_FRAME);
            result.setMatrix(bodyToEcefCoordinateTransformationMatrix, threshold);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Sets body to ECEF coordinate transformation.
     *
     * @param c body to ECEF coordinate transformation to be set.
     * @throws IllegalArgumentException if provided coordinate transformation is
     *                                  not null and is not a body to ECEF transformation.
     */
    public void setC(final CoordinateTransformation c) {
        if (c == null) {
            bodyToEcefCoordinateTransformationMatrix = null;

        } else {

            if (c.getSourceType() != FrameType.BODY_FRAME
                    || c.getDestinationType() != FrameType.EARTH_CENTERED_EARTH_FIXED_FRAME) {
                throw new IllegalArgumentException();
            }

            if (bodyToEcefCoordinateTransformationMatrix != null) {
                c.getMatrix(bodyToEcefCoordinateTransformationMatrix);
            } else {
                bodyToEcefCoordinateTransformationMatrix = c.getMatrix();
            }
        }
    }

    /**
     * Gets estimated ECEF user velocity resolved around x axis.
     *
     * @param result instance where estimated ECEF user velocity resolved around x axis will be stored.
     */
    public void getSpeedX(final Speed result) {
        result.setValue(vx);
        result.setUnit(SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Gets estimated ECEF user velocity resolved around x axis.
     *
     * @return estimated ECEF user velocity resolved around x axis.
     */
    public Speed getSpeedX() {
        return new Speed(vx, SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Sets estimated ECEF user velocity resolved around x axis.
     *
     * @param vx estimated ECEF user velocity resolved around x axis.
     */
    public void setSpeedX(final Speed vx) {
        this.vx = SpeedConverter.convert(vx.getValue().doubleValue(), vx.getUnit(), SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Gets estimated ECEF user velocity resolved around y axis.
     *
     * @param result instance where estimated ECEF user velocity resolved around y axis will be stored.
     */
    public void getSpeedY(final Speed result) {
        result.setValue(vy);
        result.setUnit(SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Gets estimated ECEF user velocity resolved around y axis.
     *
     * @return estimated ECEF velocity resolved around y axis.
     */
    public Speed getSpeedY() {
        return new Speed(vy, SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Sets estimated ECEF user velocity resolved around y axis.
     *
     * @param vy estimated ECEF user velocity resolved around y axis.
     */
    public void setSpeedY(final Speed vy) {
        this.vy = SpeedConverter.convert(vy.getValue().doubleValue(), vy.getUnit(), SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Gets estimated ECEF user velocity resolved around z axis.
     *
     * @param result instance where estimated ECEF user velocity resolved around z axis will be stored.
     */
    public void getSpeedZ(final Speed result) {
        result.setValue(vz);
        result.setUnit(SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Gets estimated ECEF user velocity resolved around z axis.
     *
     * @return estimated ECEF velocity resolved around z axis.
     */
    public Speed getSpeedZ() {
        return new Speed(vz, SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Sets estimated ECEF user velocity resolved around z axis.
     *
     * @param vz estimated ECEF velocity resolved around z axis.
     */
    public void setSpeedZ(final Speed vz) {
        this.vz = SpeedConverter.convert(vz.getValue().doubleValue(), vz.getUnit(), SpeedUnit.METERS_PER_SECOND);
    }

    /**
     * Sets estimated ECEF user velocity.
     *
     * @param vx estimated ECEF velocity resolved around x axis.
     * @param vy estimated ECEF velocity resolved around y axis.
     * @param vz estimated ECEF velocity resolved around z axis.
     */
    public void setVelocityCoordinates(final Speed vx, final Speed vy, final Speed vz) {
        setSpeedX(vx);
        setSpeedY(vy);
        setSpeedZ(vz);
    }

    /**
     * Gets estimated ECEF user velocity.
     *
     * @param result instance where estimated ECEF user velocity will be stored.
     */
    public void getEcefVelocity(final ECEFVelocity result) {

public INSLooselyCoupledKalmanState(final INSLooselyCoupledKalmanState input) {
        copyFrom(input);
    }

    /**
     * Gets estimated body to ECEF coordinate transformation matrix.
     *
     * @return estimated body to ECEF coordinate transformation matrix.
     */
    public Matrix getBodyToEcefCoordinateTransformationMatrix() {
        return bodyToEcefCoordinateTransformationMatrix;
    }

    /**
     * Sets estimated body to ECEF coordinate transformation matrix.
     *
     * @param bodyToEcefCoordinateTransformationMatrix estimated body to ECEF coordinate
     *                                                 transformation matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    public void setBodyToEcefCoordinateTransformationMatrix(final Matrix bodyToEcefCoordinateTransformationMatrix) {
        if (bodyToEcefCoordinateTransformationMatrix.getRows() != CoordinateTransformation.ROWS
                || bodyToEcefCoordinateTransformationMatrix.getColumns() != CoordinateTransformation.COLS) {
            throw new IllegalArgumentException();
        }
        this.bodyToEcefCoordinateTransformationMatrix = bodyToEcefCoordinateTransformationMatrix;
    }

    /**
     * Gets estimated ECEF user velocity resolved around x axis and expressed in meters per second (m/s).
     *
     * @return estimated ECEF user velocity resolved around x axis and expressed in meters per second (m/s).
     */
    public double getVx() {
        return vx;
    }

    /**
     * Sets estimated ECEF user velocity resolved around x axis and expressed in meters per second (m/s).
     *
     * @param vx estimated ECEF user velocity resolved around x axis and expressed in meters per second (m/s).
     */
    public void setVx(final double vx) {
        this.vx = vx;
    }

    /**
     * Gets estimated ECEF user velocity resolved around y axis and expressed in meters per second (m/s).
     *
     * @return estimated ECEF user velocity resolved around y axis and expressed in meters per second (m/s).
     */
    public double getVy() {
        return vy;
    }

    /**
     * Sets estimated ECEF user velocity resolved around y axis and expressed in meters per second (m/s).
     *
     * @param vy estimated ECEF user velocity resolved around y axis and expressed in meters per second (m/s).
     */
    public void setVy(final double vy) {
        this.vy = vy;
    }

    /**
     * Gets estimated ECEF user velocity resolved around z axis and expressed in meters per second (m/s).
     *
     * @return estimated ECEF user velocity resolved around z axis and expressed in meters per second (m/s).
     */
    public double getVz() {
        return vz;
    }

    /**
     * Sets estimated ECEF user velocity resolved around z axis and expressed in meters per second (m/s).
     *
     * @param vz estimated ECEF user velocity resolved around z axis and expressed in meters per second (m/s).
     */
    public void setVz(final double vz) {
        this.vz = vz;
    }

    /**
     * Sets estimated ECEF user velocity coordinates.
     *
     * @param vx estimated ECEF user velocity resolved around x axis and expressed in meters per second (m/s).
     * @param vy estimated ECEF user velocity resolved around y axis and expressed in meters per second (m/s).
     * @param vz estimated ECEF user velocity resolved around z axis and expressed in meters per second (m/s).
     */
    public void setVelocityCoordinates(final double vx, final double vy, final double vz) {
        this.vx = vx;
        this.vy = vy;
        this.vz = vz;
    }

    /**
     * Gets x coordinate of estimated ECEF user position expressed in meters (m).
     *
     * @return x coordinate of estimated ECEF user position expressed in meters (m).
     */
    public double getX() {
        return x;
    }

    /**
     * Sets x coordinate of estimated ECEF user position expressed in meters (m).
     *
     * @param x x coordinate of estimated ECEF user position expressed in meters (m).
     */
    public void setX(final double x) {
        this.x = x;
    }

    /**
     * Gets y coordinate of estimated ECEF user position expressed in meters (m).
     *
     * @return y coordinate of estimated ECEF user position expressed in meters (m).
     */
    public double getY() {
        return y;
    }

    /**
     * Sets y coordinate of estimated ECEF user position expressed in meters (m).
     *
     * @param y y coordinate of estimated ECEF user position expressed in meters (m).
     */
    public void setY(final double y) {
        this.y = y;
    }

    /**
     * Gets z coordinate of estimated ECEF user position expressed in meters (m).
     *
     * @return z coordinate of estimated ECEF user position expressed in meters (m).
     */
    public double getZ() {
        return z;
    }

    /**
     * Sets z coordinate of estimated ECEF user position expressed in meters (m).
     *
     * @param z z coordinate of estimated ECEF user position expressed in meters (m).
     */
    public void setZ(final double z) {
        this.z = z;
    }

    /**
     * Sets estimated ECEF user position coordinates.
     *
     * @param x x coordinate of estimated ECEF user position expressed in meters (m).
     * @param y y coordinate of estimated ECEF user position expressed in meters (m).
     * @param z z coordinate of estimated ECEF user position expressed in meters (m).
     */
    public void setPositionCoordinates(final double x, final double y, final double z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }

    /**
     * Gets estimated accelerometer bias resolved around x axis and expressed in
     * meters per squared second (m/s^2).
     *
     * @return estimated accelerometer bias resolved around x axis and expressed in
     * meters per squared second (m/s^2).
     */
    public double getAccelerationBiasX() {
        return accelerationBiasX;
    }

    /**
     * Sets estimated accelerometer bias resolved around x axis and expressed in
     * meters per squared second (m/s^2).
     *
     * @param accelerationBiasX estimated accelerometer bias resolved around x axis and
     *                          expressed in meters per squared second (m/s^2).
     */
    public void setAccelerationBiasX(final double accelerationBiasX) {
        this.accelerationBiasX = accelerationBiasX;
    }

    /**
     * Gets estimated accelerometer bias resolved around y axis and expressed in
     * meters per squared second (m/s^2).
     *
     * @return estimated accelerometer bias resolved around y axis and expressed in
     * meters per squared second (m/s^2).
     */
    public double getAccelerationBiasY() {
        return accelerationBiasY;
    }

    /**
     * Sets estimated accelerometer bias resolved around y axis and expressed in
     * meters per squared second (m/s^2).
     *
     * @param accelerationBiasY estimated accelerometer bias resolved around y axis
     *                          and expressed in meters per squared second (m/s^2).
     */
    public void setAccelerationBiasY(final double accelerationBiasY) {
        this.accelerationBiasY = accelerationBiasY;
    }

    /**
     * Gets estimated accelerometer bias resolved around z axis and expressed in
     * meters per squared second (m/s^2).
     *
     * @return estimated accelerometer bias resolved around z axis and
     * expressed in meters per squared second (m/s^2).
     */
    public double getAccelerationBiasZ() {
        return accelerationBiasZ;
    }

    /**
     * Sets estimated accelerometer bias resolved around z axis and expressed in
     * meters per squared second (m/s^2).
     *
     * @param accelerationBiasZ estimated accelerometer bias resolved around z axis
     *                          and expressed in meters per squared second (m/s^2).
     */
    public void setAccelerationBiasZ(final double accelerationBiasZ) {
        this.accelerationBiasZ = accelerationBiasZ;
    }

    /**
     * Sets estimated accelerometer bias expressed in meters per squared second (m/s^2).
     *
     * @param accelerationBiasX estimated accelerometer bias resolved around x axis and
     *                          expressed in meters per squared second (m/s^2).
     * @param accelerationBiasY estimated accelerometer bias resolved around y axis and
     *                          expressed in meters per squared second (m/s^2).
     * @param accelerationBiasZ estimated accelerometer bias resolved around z axis and
     *                          expressed in meters per squared second (m/s^2).
     */
    public void setAccelerationBiasCoordinates(
            final double accelerationBiasX, final double accelerationBiasY, final double accelerationBiasZ) {
        this.accelerationBiasX = accelerationBiasX;
        this.accelerationBiasY = accelerationBiasY;
        this.accelerationBiasZ = accelerationBiasZ;
    }

    /**
     * Gets estimated gyroscope bias resolved around x axis and expressed in
     * radians per second (rad/s).
     *
     * @return estimated gyroscope bias resolved around x axis and expressed in
     * radians per second (rad/s).
     */
    public double getGyroBiasX() {
        return gyroBiasX;
    }

    /**
     * Sets estimated gyroscope bias resolved around x axis and expressed in
     * radians per second (rad/s).
     *
     * @param gyroBiasX estimated gyroscope bias resolved around x axis and
     *                  expressed in radians per second (rad/s).
     */
    public void setGyroBiasX(final double gyroBiasX) {
        this.gyroBiasX = gyroBiasX;
    }

    /**
     * Gets estimated gyroscope bias resolved around y axis and expressed in
     * radians per second (rad/s).
     *
     * @return estimated gyroscope bias resolved around y axis and expressed
     * in radians per second (rad/s).
     */
    public double getGyroBiasY() {
        return gyroBiasY;
    }

    /**
     * Sets estimated gyroscope bias resolved around y axis and expressed in
     * radians per second (rad/s).
     *
     * @param gyroBiasY estimated gyroscope bias resolved around y axis and
     *                  expressed in radians per second (rad/s).
     */
    public void setGyroBiasY(final double gyroBiasY) {
        this.gyroBiasY = gyroBiasY;
    }

    /**
     * Gets estimated gyroscope bias resolved around z axis and expressed in
     * radians per second (rad/s).
     *
     * @return estimated gyroscope bias resolved around z axis and expressed
     * in radians per second (rad/s).
     */
    public double getGyroBiasZ() {
        return gyroBiasZ;
    }

    /**
     * Sets estimated gyroscope bias resolved around z axis and expressed in
     * radians per second (rad/s).
     *
     * @param gyroBiasZ estimated gyroscope bias resolved around z axis and
     *                  expressed in radians per second (rad/s).
     */
    public void setGyroBiasZ(final double gyroBiasZ) {
        this.gyroBiasZ = gyroBiasZ;
    }

    /**
     * Sets estimated gyroscope bias coordinates expressed in radians
     * per second (rad/s).
     *
     * @param gyroBiasX estimated gyroscope bias resolved around x axis and
     *                  expressed in radians per second (rad/s).
     * @param gyroBiasY estimated gyroscope bias resolved around y axis and
     *                  expressed in radians per second (rad/s).
     * @param gyroBiasZ estimated gyroscope bias resolved around z axis and
     *                  expressed in radians per second (rad/s).
     */
    public void setGyroBiasCoordinates(final double gyroBiasX, final double gyroBiasY, final double gyroBiasZ) {
        this.gyroBiasX = gyroBiasX;
        this.gyroBiasY = gyroBiasY;
        this.gyroBiasZ = gyroBiasZ;
    }

    /**
     * Gets Kalman filter error covariance matrix.
     * Notice that covariance is expressed in terms of ECEF coordinates.
     * If accuracy of position, attitude or velocity needs to be expressed in terms
     * of NED coordinates, their respective sub-matrices of this covariance matrix
     * must be rotated, taking into account the Jacobian of the matrix transformation
     * relating both coordinates, the covariance can be expressed following the law
     * of propagation of uncertainties
     * <a href="https://en.wikipedia.org/wiki/Propagation_of_uncertainty">(https://en.wikipedia.org/wiki/Propagation_of_uncertainty)</a>
     * as: cov(f(x)) = J*cov(x)*J'.
     *
     * @param result instance where result data will be copied to.
     * @return true if result data has been copied, false otherwise.
     */
    public boolean getCovariance(final Matrix result) {

public void setInitialBias(final AngularSpeedTriad initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialBiasX = convertAngularSpeed(initialBias.getValueX(), initialBias.getUnit());
        initialBiasY = convertAngularSpeed(initialBias.getValueY(), initialBias.getUnit());
        initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

public void setInitialBias(AngularSpeedTriad initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        initialBiasX = convertAngularSpeed(initialBias.getValueX(), initialBias.getUnit());
        initialBiasY = convertAngularSpeed(initialBias.getValueY(), initialBias.getUnit());
        initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

INSLooselyCoupledKalmanState.NUM_PARAMS, INSLooselyCoupledKalmanState.NUM_PARAMS);

        final var tmp1 = omegaIe.multiplyByScalarAndReturnNew(propagationInterval);
        final var tmp2 = phiMatrix.getSubmatrix(0, 0, 2, 2);
        tmp2.subtract(tmp1);

        phiMatrix.setSubmatrix(0, 0, 2, 2, tmp2);

        final var estCbeOld = previousState.getBodyToEcefCoordinateTransformationMatrix();
        tmp1.copyFrom(estCbeOld);
        tmp1.multiplyByScalar(propagationInterval);

        phiMatrix.setSubmatrix(0, 12, 2, 14, tmp1);
        phiMatrix.setSubmatrix(3, 9, 5, 11, tmp1);

        final var measFibb = new Matrix(BodyKinematics.COMPONENTS, 1);
        measFibb.setElementAtIndex(0, fx);
        measFibb.setElementAtIndex(1, fy);
        measFibb.setElementAtIndex(2, fz);

        estCbeOld.multiply(measFibb, tmp1);

        Utils.skewMatrix(tmp1, tmp2);
        tmp2.multiplyByScalar(-propagationInterval);

        phiMatrix.setSubmatrix(3, 0, 5, 2, tmp2);

        phiMatrix.getSubmatrix(3, 3, 5, 5, tmp1);
        tmp2.copyFrom(omegaIe);
        tmp2.multiplyByScalar(2.0 * propagationInterval);
        tmp1.subtract(tmp2);
        phiMatrix.setSubmatrix(3, 3, 5, 5, tmp1);

        final var sinPrevLat = Math.sin(previousLatitude);
        final var cosPrevLat = Math.cos(previousLatitude);
        final var sinPrevLat2 = sinPrevLat * sinPrevLat;
        final var cosPrevLat2 = cosPrevLat * cosPrevLat;

        // From (2.137)
        final var geocentricRadius = EARTH_EQUATORIAL_RADIUS_WGS84
                / Math.sqrt(1.0 - Math.pow(EARTH_ECCENTRICITY * sinPrevLat, 2.0)) * Math.sqrt(cosPrevLat2
                + Math.pow(1.0 - EARTH_ECCENTRICITY * EARTH_ECCENTRICITY, 2.0) * sinPrevLat2);

        final var prevX = previousState.getX();
        final var prevY = previousState.getY();
        final var prevZ = previousState.getZ();
        final var gravity = ECEFGravityEstimator.estimateGravityAndReturnNew(prevX, prevY, prevZ);

        final var previousPositionNorm = Math.sqrt(prevX * prevX + prevY * prevY + prevZ * prevZ);

        final var estRebeOld = new Matrix(com.irurueta.navigation.frames.ECEFPosition.COMPONENTS, 1);
        estRebeOld.setElementAtIndex(0, prevX);
        estRebeOld.setElementAtIndex(1, prevY);
        estRebeOld.setElementAtIndex(2, prevZ);

        final var g = gravity.asMatrix();
        g.multiplyByScalar(-2.0 * propagationInterval / geocentricRadius);

        final var estRebeOldTrans = estRebeOld.transposeAndReturnNew();
        estRebeOldTrans.multiplyByScalar(1.0 / previousPositionNorm);

        g.multiply(estRebeOldTrans, tmp1);

        phiMatrix.setSubmatrix(3, 6, 5, 8, tmp1);

        for (var i = 0; i < com.irurueta.navigation.frames.ECEFPosition.COMPONENTS; i++) {

if (estimatedMa == null) {
            estimatedMa = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        } else {
            estimatedMa.initialize(0.0);
        }

        estimatedMa.setElementAt(0, 0, sx);
        estimatedMa.setElementAt(1, 0, myx);
        estimatedMa.setElementAt(2, 0, mzx);

        estimatedMa.setElementAt(0, 1, mxy);
        estimatedMa.setElementAt(1, 1, sy);
        estimatedMa.setElementAt(2, 1, mzy);

        estimatedMa.setElementAt(0, 2, mxz);
        estimatedMa.setElementAt(1, 2, myz);
        estimatedMa.setElementAt(2, 2, sz);

        estimatedCovariance = fitter.getCovar();
        estimatedChiSq = fitter.getChisq();
        estimatedMse = fitter.getMse();
    }

    /**
     * Sets input data into Levenberg-Marquardt fitter.
     *
     * @throws WrongSizeException never happens.
     */
    private void setInputData() throws WrongSizeException {
        // set input data using:
        // fmeasx = bx + ftruex + sx * ftruex + mxy * ftruey + mxz * ftruez
        // fmeasy = by + myx * ftruex + ftruey + sy * ftruey + myz * ftruez
        // fmeasz = bz + mzx * ftruex + mzy * ftruey + ftruez + sz * ftruez

        final var expectedKinematics = new BodyKinematics();

        final var numMeasurements = measurements.size();
        final var x = new Matrix(numMeasurements, BodyKinematics.COMPONENTS);
        final var y = new Matrix(numMeasurements, BodyKinematics.COMPONENTS);
        final var specificForceStandardDeviations = new double[numMeasurements];
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredKinematics = measurement.getKinematics();
            final var ecefFrame = measurement.getFrame();
            final var previousEcefFrame = measurement.getPreviousFrame();
            final var timeInterval = measurement.getTimeInterval();

            ECEFKinematicsEstimator.estimateKinematics(timeInterval, ecefFrame, previousEcefFrame, expectedKinematics);

            final var fMeasX = measuredKinematics.getFx();
            final var fMeasY = measuredKinematics.getFy();
            final var fMeasZ = measuredKinematics.getFz();

            final var fTrueX = expectedKinematics.getFx();
            final var fTrueY = expectedKinematics.getFy();
            final var fTrueZ = expectedKinematics.getFz();

            x.setElementAt(i, 0, fTrueX);
            x.setElementAt(i, 1, fTrueY);
            x.setElementAt(i, 2, fTrueZ);

            y.setElementAt(i, 0, fMeasX);
            y.setElementAt(i, 1, fMeasY);
            y.setElementAt(i, 2, fMeasZ);

            specificForceStandardDeviations[i] = measurement.getSpecificForceStandardDeviation();
            i++;
        }

        fitter.setInputData(x, y, specificForceStandardDeviations);
    }

    /**
     * Converts acceleration value and unit to meters per squared second.
     *
     * @param value acceleration value.
     * @param unit  unit of acceleration value.
     * @return converted value.
     */
    private static double convertAcceleration(final double value, final AccelerationUnit unit) {
        return AccelerationConverter.convert(value, unit, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Converts acceleration instance to meters per squared second.
     *
     * @param acceleration acceleration instance to be converted.
     * @return converted value.
     */
    private static double convertAcceleration(final Acceleration acceleration) {
        return convertAcceleration(acceleration.getValue().doubleValue(), acceleration.getUnit());
    }
}

final RobustKnownFrameMagnetometerCalibratorListener listener) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurements() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start the estimator.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or no.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Gets Earth's magnetic model.
     *
     * @return Earth's magnetic model or null if not provided.
     */
    public WorldMagneticModel getMagneticModel() {
        return magneticModel;
    }

    /**
     * Sets Earth's magnetic model.
     *
     * @param magneticModel Earth's magnetic model to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setMagneticModel(final WorldMagneticModel magneticModel) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.magneticModel = magneticModel;
    }

    /**
     * Indicates whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @return indicates whether a linear calibrator is used or not for
     * preliminary solutions.
     */
    public boolean isLinearCalibratorUsed() {
        return useLinearCalibrator;
    }

    /**
     * Specifies whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @param linearCalibratorUsed indicates whether a linear calibrator is used
     *                             or not for preliminary solutions.
     * @throws LockedException if calibrator is currently running.
     */
    public void setLinearCalibratorUsed(final boolean linearCalibratorUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        useLinearCalibrator = linearCalibratorUsed;
    }

    /**
     * Indicates whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @return true if preliminary solutions must be refined after an initial linear solution, false
     * otherwise.
     */
    public boolean isPreliminarySolutionRefined() {
        return refinePreliminarySolutions;
    }

    /**
     * Specifies whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @param preliminarySolutionRefined true if preliminary solutions must be refined after an
     *                                   initial linear solution, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPreliminarySolutionRefined(final boolean preliminarySolutionRefined) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        refinePreliminarySolutions = preliminarySolutionRefined;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @return array containing x,y,z components of estimated magnetometer
     * hard-iron biases.
     */
    @Override
    public double[] getEstimatedHardIron() {

running = false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing g-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed for both
     * the accelerometer and gyroscope.
     *
     * @throws AlgebraException if there are numerical errors.
     */
    private void calibrateCommonAxis() throws AlgebraException {
        // The gyroscope model is:
        // Ωmeas = bg + (I + Mg) * Ωtrue + Gg * ftrue + w

        // Ideally a least squares solution tries to minimize noise component, so:
        // Ωmeas = bg + (I + Mg) * Ωtrue + Gg * ftrue

        // Hence:
        // [Ωmeasx] = [bx] + ( [1   0   0] + [sx    mxy    mxz]) [Ωtruex] + [g11   g12   g13][ftruex]
        // [Ωmeasy]   [by]     [0   1   0]   [myx   sy     myz]  [Ωtruey]   [g21   g22   g23][ftruey]
        // [Ωmeasz]   [bz]     [0   0   1]   [mzx   mzy    sz ]  [Ωtruez]   [g31   g32   g33][ftruez]

        // where myx = mzx = mzy = 0

        // Hence:
        // [Ωmeasx] = [bx] + ( [1   0   0] + [sx    mxy    mxz]) [Ωtruex] + [g11   g12   g13][ftruex]
        // [Ωmeasy]   [by]     [0   1   0]   [0     sy     myz]  [Ωtruey]   [g21   g22   g23][ftruey]
        // [Ωmeasz]   [bz]     [0   0   1]   [0     0      sz ]  [Ωtruez]   [g31   g32   g33][ftruez]


        // [Ωmeasx] = [bx] + ( [1+sx  mxy    mxz ]) [Ωtruex] + [g11   g12   g13][ftruex]
        // [Ωmeasy]   [by]     [0     1+sy   myz ]  [Ωtruey]   [g21   g22   g23][ftruey]
        // [Ωmeasz]   [bz]     [0     0      1+sz]  [Ωtruez]   [g31   g32   g33][ftruez]

        // Ωmeasx = bx + (1+sx) * Ωtruex + mxy * Ωtruey + mxz * Ωtruez + g11 * ftruex + g12 * ftruey + g13 * ftruez
        // Ωmeasy = by + (1+sy) * Ωtruey + myz * Ωtruez + g21 * ftruex * g22 * ftruey + g23 * ftruez
        // Ωmeasz = bz + (1+sz) * Ωtruez + g31 * ftruex + g32 * ftruey + g33 * ftruez

        // Where the unknowns are: sx, sy, sz, mxy mxz, myz, g11, g12, g13, g21, g22, g23, g31, g32, g33
        // Reordering:
        // Ωmeasx = bx + Ωtruex + sx * Ωtruex + mxy * Ωtruey + mxz * Ωtruez + g11 * ftruex + g12 * ftruey + g13 * ftruez
        // Ωmeasy = by + Ωtruey + sy * Ωtruey + myz * Ωtruez + g21 * ftruex * g22 * ftruey + g23 * ftruez
        // Ωmeasz = bz + Ωtruez + sz * Ωtruez + g31 * ftruex + g32 * ftruey + g33 * ftruez

        // Ωmeasx - Ωtruex - bx = sx * Ωtruex + mxy * Ωtruey + mxz * Ωtruez + g11 * ftruex + g12 * ftruey + g13 * ftruez
        // Ωmeasy - Ωtruey - by = sy * Ωtruey + myz * Ωtruez + g21 * ftruex * g22 * ftruey + g23 * ftruez
        // Ωmeasz - Ωtruez - bz = sz * Ωtruez + g31 * ftruex + g32 * ftruey + g33 * ftruez

        // [Ωtruex  0       0       Ωtruey  Ωtruez  0       ftruex  ftruey  ftruez  0       0       0       0       0       0     ][sx ] =  [Ωmeasx - Ωtruex - bx]
        // [0       Ωtruey  0       0       0       Ωtruez  0       0       0       ftruex  ftruey  ftruez  0       0       0     ][sy ]    [Ωmeasy - Ωtruey - by]
        // [0       0       Ωtruez  0       0       0       0       0       0       0       0       0       ftruex  ftruey  ftruez][sz ]    [Ωmeasz - Ωtruez - bz]
        //                                                                                                                         [mxy]
        //                                                                                                                         [mxz]
        //                                                                                                                         [myz]
        //                                                                                                                         [g11]
        //                                                                                                                         [g12]
        //                                                                                                                         [g13]
        //                                                                                                                         [g21]
        //                                                                                                                         [g22]
        //                                                                                                                         [g23]
        //                                                                                                                         [g31]
        //                                                                                                                         [g32]
        //                                                                                                                         [g33]

        final var expectedKinematics = new BodyKinematics();

        final var rows = EQUATIONS_PER_MEASUREMENT * measurements.size();
        final var a = new Matrix(rows, COMMON_Z_AXIS_UNKNOWNS);
        final var b = new Matrix(rows, 1);
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredKinematics = measurement.getKinematics();
            final var ecefFrame = measurement.getFrame();
            final var previousEcefFrame = measurement.getPreviousFrame();
            final var timeInterval = measurement.getTimeInterval();

            ECEFKinematicsEstimator.estimateKinematics(timeInterval, ecefFrame, previousEcefFrame, expectedKinematics);

            final var omegaMeasX = measuredKinematics.getAngularRateX();
            final var omegaMeasY = measuredKinematics.getAngularRateY();
            final var omegaMeasZ = measuredKinematics.getAngularRateZ();

            final var omegaTrueX = expectedKinematics.getAngularRateX();
            final var omegaTrueY = expectedKinematics.getAngularRateY();
            final var omegaTrueZ = expectedKinematics.getAngularRateZ();

            final var fTrueX = expectedKinematics.getFx();
            final var fTrueY = expectedKinematics.getFy();
            final var fTrueZ = expectedKinematics.getFz();

            a.setElementAt(i, 0, omegaTrueX);

b.setElementAtIndex(2, bz);

            g.setElementAt(0, 0, g11);
            g.setElementAt(1, 0, g21);
            g.setElementAt(2, 0, g31);

            g.setElementAt(0, 1, g12);
            g.setElementAt(1, 1, g22);
            g.setElementAt(2, 1, g32);

            g.setElementAt(0, 2, g13);
            g.setElementAt(1, 2, g23);
            g.setElementAt(2, 2, g33);

            // fix kinematics
            final var numItems = measuredSequence.getItemsCount();
            final var measuredItems = measuredSequence.getSortedItems();
            final var fixedItems = fixedSequence.getSortedItems();
            for (var j = 0; j < numItems; j++) {
                final var measuredItem = measuredItems.get(j);
                final var fixedItem = fixedItems.get(j);

                fixKinematics(measuredItem.getKinematics(), fixedItem.getKinematics());
            }


            // integrate fixed sequence to obtain attitude change
            QuaternionIntegrator.integrateGyroSequence(fixedSequence, QuaternionStepIntegratorType.RUNGE_KUTTA, q);

            startPoint.setInhomogeneousCoordinates(point[0], point[1], point[2]);
            q.inverse();
            q.rotate(startPoint, endPoint);

            expectedEndPoint.setInhomogeneousCoordinates(point[3], point[4], point[5]);

            return expectedEndPoint.distanceTo(endPoint);

        } catch (final AlgebraException | RotationException e) {
            throw new EvaluationException(e);
        }
    }

    /**
     * Fixes provided kinematics with provided accelerometer parameters and
     * current gyroscope parameters.
     *
     * @param kinematics kinematics to be fixed with current values.
     * @param result     kinematics where result will be stored.
     * @throws AlgebraException if for some reason kinematics
     */
    private void fixKinematics(final BodyKinematics kinematics, final BodyKinematics result) throws AlgebraException {

        // Ωmeas = bg + (I + Mg) * Ωtrue + Gg * ftrue
        // Ωmeas = M*(Ωtrue + b + G * ftrue)

        // M = I + Mg
        // bg = M*b --> b = M^-1*bg
        // Gg = M*G --> G = M^-1*Gg

        // Ωtrue = M^-1 * Ωmeas - b - G*ftrue

        // fix specific force
        measuredSpecificForce.setElementAtIndex(0, kinematics.getFx());
        measuredSpecificForce.setElementAtIndex(1, kinematics.getFy());
        measuredSpecificForce.setElementAtIndex(2, kinematics.getFz());

        accelerationFixer.fix(measuredSpecificForce, trueSpecificForce);

        // fix angular rate
        measuredAngularRate.setElementAtIndex(0, kinematics.getAngularRateX());
        measuredAngularRate.setElementAtIndex(1, kinematics.getAngularRateY());
        measuredAngularRate.setElementAtIndex(2, kinematics.getAngularRateZ());

        g.multiply(trueSpecificForce, tmp);
        invM.multiply(measuredAngularRate, trueAngularRate);
        trueAngularRate.subtract(b);
        trueAngularRate.subtract(tmp);

        result.setSpecificForceCoordinates(
                trueSpecificForce.getElementAtIndex(0),
                trueSpecificForce.getElementAtIndex(1),
                trueSpecificForce.getElementAtIndex(2));

        result.setAngularRateCoordinates(
                trueAngularRate.getElementAtIndex(0),
                trueAngularRate.getElementAtIndex(1),
                trueAngularRate.getElementAtIndex(2));
    }

    /**
     * Resets any previous estimations.
     */
    private void reset() {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities) and containing the standard
     * deviations of accelerometer and gyroscope measurements.
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate the a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public Collection<StandardDeviationFrameBodyKinematics> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities) and containing the standard
     * deviations of accelerometer and gyroscope measurements.
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate the a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @param measurements collection of body kinematics measurements taken at different
     *                     frames (positions, orientations and velocities).
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final Collection<? extends StandardDeviationFrameBodyKinematics> measurements)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        //noinspection unchecked
        this.measurements = (Collection<StandardDeviationFrameBodyKinematics>) measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public AccelerometerCalibratorMeasurementType getMeasurementType() {
        return AccelerometerCalibratorMeasurementType.STANDARD_DEVIATION_FRAME_BODY_KINEMATICS;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return false;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return false;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    @Override
    public KnownBiasAndFrameAccelerometerNonLinearLeastSquaresCalibratorListener getListener() {

initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public Collection<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate the a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @param measurements collection of body magnetic flux density measurements
     *                     taken at different frames (positions, orientations
     *                     and velocities).
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setMeasurements(final Collection<? extends StandardDeviationFrameBodyMagneticFluxDensity> measurements)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        //noinspection unchecked
        this.measurements = (Collection<StandardDeviationFrameBodyMagneticFluxDensity>) measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public MagnetometerCalibratorMeasurementType getMeasurementType() {
        return MagnetometerCalibratorMeasurementType.STANDARD_DEVIATION_FRAME_BODY_MAGNETIC_FLUX_DENSITY;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return false;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return false;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer.
     * When enabled, this eliminates 3 variables from Mm (soft-iron) matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer, false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Mm matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for
     *                       accelerometer, gyroscope and magnetometer, false
     *                       otherwise.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this calibrator.
     *
     * @return listener to handle events raised by this calibrator.
     */
    @Override
    public KnownFrameMagnetometerNonLinearLeastSquaresCalibratorListener getListener() {

initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @return collection of sequences of timestamped body kinematics
     * measurements.
     */
    @Override
    public List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> getSequences() {

initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

    /**
     * Gets collection of sequences of timestamped body kinematics
     * measurements taken at a given position where the device moves freely
     * with different orientations.
     *
     * @return collection of sequences of timestamped body kinematics
     * measurements.
     */
    @Override
    public List<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>> getSequences() {

initialBiasZ = convertAngularSpeed(initialBias.getValueZ(), initialBias.getUnit());
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @return initial gyroscope scale factors and cross coupling errors
     * matrix.
     */
    @Override
    public Matrix getInitialMg() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMg(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope scale factors and cross coupling errors
     * matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial gyroscope scale factors and cross coupling errors matrix.
     *
     * @param initialMg initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMg(final Matrix initialMg) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMg.getRows() != BodyKinematics.COMPONENTS || initialMg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMg.getElementAtIndex(0);
        initialMyx = initialMg.getElementAtIndex(1);
        initialMzx = initialMg.getElementAtIndex(2);

        initialMxy = initialMg.getElementAtIndex(3);
        initialSy = initialMg.getElementAtIndex(4);
        initialMzy = initialMg.getElementAtIndex(5);

        initialMxz = initialMg.getElementAtIndex(6);
        initialMyz = initialMg.getElementAtIndex(7);
        initialSz = initialMg.getElementAtIndex(8);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing initial g-dependent cross biases.
     */
    @Override
    public Matrix getInitialGg() {
        return new Matrix(initialGg);
    }

    /**
     * Gets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialGg(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        result.copyFrom(initialGg);
    }

    /**
     * Sets initial G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @param initialGg g-dependent cross biases.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void setInitialGg(final Matrix initialGg) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialGg.getRows() != BodyKinematics.COMPONENTS || initialGg.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialGg.copyTo(this.initialGg);
    }

public void setListener(final RobustKnownBiasAndFrameAccelerometerCalibratorListener listener)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurements() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Indicates whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @return indicates whether a linear calibrator is used or not for
     * preliminary solutions.
     */
    public boolean isLinearCalibratorUsed() {
        return useLinearCalibrator;
    }

    /**
     * Specifies whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @param linearCalibratorUsed indicates whether a linear calibrator is used
     *                             or not for preliminary solutions.
     * @throws LockedException if calibrator is currently running.
     */
    public void setLinearCalibratorUsed(final boolean linearCalibratorUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        useLinearCalibrator = linearCalibratorUsed;
    }

    /**
     * Indicates whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @return true if preliminary solutions must be refined after an initial linear solution, false
     * otherwise.
     */
    public boolean isPreliminarySolutionRefined() {
        return refinePreliminarySolutions;
    }

    /**
     * Specifies whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @param preliminarySolutionRefined true if preliminary solutions must be refined after an
     *                                   initial linear solution, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPreliminarySolutionRefined(final boolean preliminarySolutionRefined) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        refinePreliminarySolutions = preliminarySolutionRefined;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {

public void setListener(final RobustKnownBiasAndFrameGyroscopeCalibratorListener listener) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurementsOrSequences() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Indicates whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @return indicates whether a linear calibrator is used or not for
     * preliminary solutions.
     */
    public boolean isLinearCalibratorUsed() {
        return useLinearCalibrator;
    }

    /**
     * Specifies whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @param linearCalibratorUsed indicates whether a linear calibrator is used
     *                             or not for preliminary solutions.
     * @throws LockedException if calibrator is currently running.
     */
    public void setLinearCalibratorUsed(final boolean linearCalibratorUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        useLinearCalibrator = linearCalibratorUsed;
    }

    /**
     * Indicates whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @return true if preliminary solutions must be refined after an initial linear solution, false
     * otherwise.
     */
    public boolean isPreliminarySolutionRefined() {
        return refinePreliminarySolutions;
    }

    /**
     * Specifies whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @param preliminarySolutionRefined true if preliminary solutions must be refined after an
     *                                   initial linear solution, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPreliminarySolutionRefined(final boolean preliminarySolutionRefined) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        refinePreliminarySolutions = preliminarySolutionRefined;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {

running = false;
        }
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {
        return estimatedMa;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 1) : null;
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed for both
     * the accelerometer and gyroscope.
     *
     * @throws AlgebraException if there are numerical errors.
     */
    private void calibrateCommonAxis() throws AlgebraException {
        // The accelerometer model is:
        // fmeas = ba + (I + Ma) * ftrue + w

        // Ideally a least squares solution tries to minimize noise component, so:
        // fmeas = ba + (I + Ma) * ftrue

        // Hence:
        // [fmeasx] = [bx] + ( [1  0   0] + [sx    mxy mxz])   [ftruex]
        // [fmeasy] = [by]     [0  1   0]   [myx   sy  myz]    [ftruey]
        // [fmeasz] = [bz]     [0  0   1]   [mzx   mzy sz ]    [ftruez]

        // where myx = mzx = mzy = 0

        // Hence:
        // [fmeasx] = [bx] + ( [1  0   0] + [sx    mxy mxz])   [ftruex]
        // [fmeasy] = [by]     [0  1   0]   [0     sy  myz]    [ftruey]
        // [fmeasz] = [bz]     [0  0   1]   [0     0   sz ]    [ftruez]

        // [fmeasx] = [bx] +   [1+sx   mxy     mxz ][ftruex]
        // [fmeasy]   [by]     [0      1+sy    myz ][ftruey]
        // [fmeasz]   [bz]     [0      0       1+sz][ftruez]

        // fmeasx = bx + (1+sx) * ftruex + mxy * ftruey + mxz * ftruez
        // fmeasy = by + (1+sy) * ftruey + myz * ftruez
        // fmeasz = bz + (1+sz) * ftruez

        // Where the unknowns are: sx, sy, sz, mxy mxz, myz
        // Reordering:
        // fmeasx = bx + ftruex + sx * ftruex + mxy * ftruey + mxz * ftruez
        // fmeasy = by + ftruey + sy * ftruey + myz * ftruez
        // fmeasz = bz + ftruez + sz * ftruez

        // fmeasx - ftruex - bx = sx * ftruex + mxy * ftruey + mxz * ftruez
        // fmeasy - ftruey - by = sy * ftruey + myz * ftruez
        // fmeasz - ftruez - bz = sz * ftruez

        // [ftruex  0       0       ftruey  ftruez  0     ][sx ] = [fmeasx - ftruex - bx]
        // [0       ftruey  0       0       0       ftruez][sy ]   [fmeasy - ftruey - by]
        // [0       0       ftruez  0       0       0     ][sz ]   [fmeasz - ftruez - bz]
        //                                                 [mxy]
        //                                                 [mxz]
        //                                                 [myz]

        final var expectedKinematics = new BodyKinematics();

        final var rows = EQUATIONS_PER_MEASUREMENT * measurements.size();
        final var a = new Matrix(rows, COMMON_Z_AXIS_UNKNOWNS);
        final var b = new Matrix(rows, 1);
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredKinematics = measurement.getKinematics();
            final var ecefFrame = measurement.getFrame();
            final var previousEcefFrame = measurement.getPreviousFrame();
            final var timeInterval = measurement.getTimeInterval();

            ECEFKinematicsEstimator.estimateKinematics(timeInterval, ecefFrame, previousEcefFrame, expectedKinematics);

            final var fMeasX = measuredKinematics.getFx();
            final var fMeasY = measuredKinematics.getFy();
            final var fMeasZ = measuredKinematics.getFz();

            final var fTrueX = expectedKinematics.getFx();
            final var fTrueY = expectedKinematics.getFy();
            final var fTrueZ = expectedKinematics.getFz();

            a.setElementAt(i, 0, fTrueX);

initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a list of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public List<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a list of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate the a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @param measurements collection of body magnetic flux density measurements
     *                     taken at different frames (positions, orientations
     *                     and velocities).
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setMeasurements(
            final List<StandardDeviationFrameBodyMagneticFluxDensity> measurements) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public MagnetometerCalibratorMeasurementType getMeasurementType() {
        return MagnetometerCalibratorMeasurementType.STANDARD_DEVIATION_FRAME_BODY_MAGNETIC_FLUX_DENSITY;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return true;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer.
     * When enabled, this eliminates 3 variables from Mm (soft-iron) matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer, false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Mm matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for
     *                       accelerometer, gyroscope and magnetometer, false
     *                       otherwise.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this calibrator.
     *
     * @return listener to handle events raised by this calibrator.
     */
    public RobustKnownFrameMagnetometerCalibratorListener getListener() {

hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public List<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {
        return measurements;
    }

    /**
     * Sets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @param measurements collection of body magnetic flux density
     *                     measurements at a known position and timestamp
     *                     with unknown orientations.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final List<StandardDeviationBodyMagneticFluxDensity> measurements)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public MagnetometerCalibratorMeasurementType getMeasurementType() {
        return MagnetometerCalibratorMeasurementType.STANDARD_DEVIATION_BODY_MAGNETIC_FLUX_DENSITY;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return true;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer.
     * When enabled, this eliminates 3 variables from Mm (soft-iron) matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer,
     * gyroscope and magnetometer, false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Mm matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for
     *                       accelerometer, gyroscope and magnetometer, false
     *                       otherwise.
     * @throws LockedException if estimator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this calibrator.
     *
     * @return listener to handle events raised by this calibrator.
     */
    public RobustKnownHardIronMagneticFluxDensityNormMagnetometerCalibratorListener getListener() {

}

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return array containing x,y,z components of estimated accelerometer biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where estimated accelerometer biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return column matrix containing x,y,z components of estimated accelerometer
     * biases
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFx() {

estimateKinematics(timeInterval, c, oldC, velocity, oldVelocity,
                position.getInhomX(), position.getInhomY(), position.getInhomZ(), result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            boy-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param position     body position expressed in meters (m) with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static void estimateKinematics(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final Speed vx, final Speed vy, final Speed vz, final Speed oldVx, final Speed oldVy, final Speed oldVz,
            final Point3D position, final BodyKinematics result) {
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz,
                position.getInhomX(), position.getInhomY(), position.getInhomZ(), result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs.
     * @param c            boy-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param position     body position expressed in meters (m) with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static void estimateKinematics(
            final Time timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final Speed vx, final Speed vy, final Speed vz, final Speed oldVx, final Speed oldVy, final Speed oldVz,
            final Point3D position, final BodyKinematics result) {
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz,
                position.getInhomX(), position.getInhomY(), position.getInhomZ(), result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @return a new body kinematics instance.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static BodyKinematics estimateKinematicsAndReturnNew(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final double vx, final double vy, final double vz,
            final double oldVx, final double oldVy, final double oldVz,
            final double x, final double y, final double z) {
        final var result = new BodyKinematics();
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz, x, y, z, result);
        return result;
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between.
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @return a new body kinematics instance.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static BodyKinematics estimateKinematicsAndReturnNew(
            final Time timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final double vx, final double vy, final double vz,
            final double oldVx, final double oldVy, final double oldVz,
            final double x, final double y, final double z) {
        final var result = new BodyKinematics();
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz, x, y, z, result);
        return result;
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            boy-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param velocity     velocity of body frame with respect ECEF frame.
     * @param oldVelocity  previous velocity of body frame with respect ECEF frame.
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @return a new body kinematics instance.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static BodyKinematics estimateKinematicsAndReturnNew(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,

setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets a list of body kinematics measurements taken at different
     * frames (positions, orientations and velocities) and containing the standard
     * deviations of accelerometer and gyroscope measurements.
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate the a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body kinematics measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public List<StandardDeviationFrameBodyKinematics> getMeasurements() {
        return measurements;
    }

    /**
     * Sets a list of body kinematics measurements taken at different
     * frames (positions, orientations and velocities) and containing the standard
     * deviations of accelerometer and gyroscope measurements.
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate the a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @param measurements collection of body kinematics measurements taken at different
     *                     frames (positions, orientations and velocities).
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setMeasurements(final List<StandardDeviationFrameBodyKinematics> measurements) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.measurements = measurements;
    }

    /**
     * Indicates the type of measurement used by this calibrator.
     *
     * @return type of measurement used by this calibrator.
     */
    @Override
    public AccelerometerCalibratorMeasurementType getMeasurementType() {
        return AccelerometerCalibratorMeasurementType.STANDARD_DEVIATION_FRAME_BODY_KINEMATICS;
    }

    /**
     * Indicates whether this calibrator requires ordered measurements in a
     * list or not.
     *
     * @return true if measurements must be ordered, false otherwise.
     */
    @Override
    public boolean isOrderedMeasurementsRequired() {
        return true;
    }

    /**
     * Indicates whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @return true if z-axis is assumed to be common for accelerometer and gyroscope,
     * false otherwise.
     */
    @Override
    public boolean isCommonAxisUsed() {
        return commonAxisUsed;
    }

    /**
     * Specifies whether z-axis is assumed to be common for accelerometer and
     * gyroscope.
     * When enabled, this eliminates 3 variables from Ma matrix.
     *
     * @param commonAxisUsed true if z-axis is assumed to be common for accelerometer
     *                       and gyroscope, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setCommonAxisUsed(final boolean commonAxisUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.commonAxisUsed = commonAxisUsed;
    }

    /**
     * Gets listener to handle events raised by this estimator.
     *
     * @return listener to handle events raised by this estimator.
     */
    public RobustKnownBiasAndFrameAccelerometerCalibratorListener getListener() {

}

    /**
     * Gets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasX() {
        return biasX;
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final double biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = biasX;
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasY() {
        return biasY;
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final double biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = biasY;
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public double getBiasZ() {
        return biasZ;
    }

    /**
     * Sets z-coordinate of known accelerometer bias.
     * This is expressed in meters per squared second (m/s^2).
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = biasZ;
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @return x-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasXAsAcceleration() {
        return new Acceleration(biasX, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets x-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasXAsAcceleration(final Acceleration result) {
        result.setValue(biasX);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets x-coordinate of known accelerometer bias.
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasX(final Acceleration biasX) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasX = convertAcceleration(biasX);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @return y-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasYAsAcceleration() {
        return new Acceleration(biasY, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets y-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasYAsAcceleration(final Acceleration result) {
        result.setValue(biasY);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets y-coordinate of known accelerometer bias.
     *
     * @param biasY y-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasY(final Acceleration biasY) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasY = convertAcceleration(biasY);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @return z-coordinate of known accelerometer bias.
     */
    @Override
    public Acceleration getBiasZAsAcceleration() {
        return new Acceleration(biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Gets z-coordinate of known accelerometer bias.
     *
     * @param result instance where result data will be stored.
     */
    @Override
    public void getBiasZAsAcceleration(final Acceleration result) {
        result.setValue(biasZ);
        result.setUnit(AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets z-coordinate of known accelerometer bias to be used to find a solution.
     *
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasZ(final Acceleration biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Sets known bias coordinates of accelerometer expressed in meters
     * per squared second (m/s^2).
     *
     * @param biasX x-coordinate of known accelerometer bias.
     * @param biasY y-coordinate of known accelerometer bias.
     * @param biasZ z-coordinate of known accelerometer bias.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBiasCoordinates(final double biasX, final double biasY, final double biasZ) throws LockedException {
        if (running) {
            throw new LockedException();
        }

public void setListener(final RobustKnownHardIronPositionAndInstantMagnetometerCalibratorListener listener)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurements() {
        return commonAxisUsed ? MINIMUM_MEASUREMENTS_COMMON_Z_AXIS : MINIMUM_MEASUREMENTS_GENERAL;
    }

    /**
     * Indicates whether calibrator is ready to start the estimator.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= getMinimumRequiredMeasurements()
                && position != null && year != null;
    }

    /**
     * Indicates whether calibrator is currently running or no.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Gets Earth's magnetic model.
     *
     * @return Earth's magnetic model or null if not provided.
     */
    public WorldMagneticModel getMagneticModel() {
        return magneticModel;
    }

    /**
     * Sets Earth's magnetic model.
     *
     * @param magneticModel Earth's magnetic model to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setMagneticModel(final WorldMagneticModel magneticModel) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.magneticModel = magneticModel;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {

super(sequences, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                accelerometerBias, accelerometerMa, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sequence.
     * The larger the score value the better the quality of the sequence.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sequence.
     * The larger the score value the better the quality of the sequence.
     *
     * @param qualityScores quality scores corresponding to each sequence.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether calibrator is ready to find a solution.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == sequences.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates gyroscope calibration parameters containing bias, scale factors,
     * cross-coupling errors and G-dependent coupling.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return sequences.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(sequences.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROSACRobustEasyGyroscopeCalibrator.this.isReady();

super(position, measurements, commonAxisUsed, bias, initialMa, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples
     *                                  (10 or 13).
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether calibrator is ready to find a solution.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        gravityNorm = computeGravityNorm();

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROSACRobustKnownBiasAndPositionAccelerometerCalibrator.this.isReady();

estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether calibrator is ready to find a solution.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates gyroscope calibration parameters containing scale factors
     * cross-coupling errors and g-dependant cross biases.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROSACRobustKnownBiasTurntableGyroscopeCalibrator.this.isReady();

super(groundTruthMagneticFluxDensityNorm, measurements, commonAxisUsed, initialHardIron, initialMm, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether calibrator is ready to find a solution.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates magnetometer calibration parameters containing hard-iron
     * bias and soft-iron scale factors and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROSACRobustKnownMagneticFluxDensityNormMagnetometerCalibrator.this.isReady();

this(measurements, bias, commonAxisUsed, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<Matrix>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(final int[] samplesIndices, final List<Matrix> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final Matrix currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROSACRobustKnownBiasAndFrameAccelerometerCalibrator.this.isReady();

super(measurements, commonAxisUsed, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether calibrator is ready to find a solution.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing bias, scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROSACRobustKnownFrameAccelerometerCalibrator.this.isReady();

public int getMinimumRequiredMeasurements() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Indicates whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @return indicates whether a linear calibrator is used or not for
     * preliminary solutions.
     */
    public boolean isLinearCalibratorUsed() {
        return useLinearCalibrator;
    }

    /**
     * Specifies whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @param linearCalibratorUsed indicates whether a linear calibrator is used
     *                             or not for preliminary solutions.
     * @throws LockedException if calibrator is currently running.
     */
    public void setLinearCalibratorUsed(final boolean linearCalibratorUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        useLinearCalibrator = linearCalibratorUsed;
    }

    /**
     * Indicates whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @return true if preliminary solutions must be refined after an initial linear solution, false
     * otherwise.
     */
    public boolean isPreliminarySolutionRefined() {
        return refinePreliminarySolutions;
    }

    /**
     * Specifies whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @param preliminarySolutionRefined true if preliminary solutions must be refined after an
     *                                   initial linear solution, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPreliminarySolutionRefined(final boolean preliminarySolutionRefined) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        refinePreliminarySolutions = preliminarySolutionRefined;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {

public int getMinimumRequiredMeasurements() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Indicates whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @return indicates whether a linear calibrator is used or not for
     * preliminary solutions.
     */
    public boolean isLinearCalibratorUsed() {
        return useLinearCalibrator;
    }

    /**
     * Specifies whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @param linearCalibratorUsed indicates whether a linear calibrator is used
     *                             or not for preliminary solutions.
     * @throws LockedException if calibrator is currently running.
     */
    public void setLinearCalibratorUsed(final boolean linearCalibratorUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        useLinearCalibrator = linearCalibratorUsed;
    }

    /**
     * Indicates whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @return true if preliminary solutions must be refined after an initial linear solution, false
     * otherwise.
     */
    public boolean isPreliminarySolutionRefined() {
        return refinePreliminarySolutions;
    }

    /**
     * Specifies whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @param preliminarySolutionRefined true if preliminary solutions must be refined after an
     *                                   initial linear solution, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPreliminarySolutionRefined(final boolean preliminarySolutionRefined) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        refinePreliminarySolutions = preliminarySolutionRefined;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {

public int getMinimumRequiredMeasurements() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Indicates whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @return indicates whether a linear calibrator is used or not for
     * preliminary solutions.
     */
    public boolean isLinearCalibratorUsed() {
        return useLinearCalibrator;
    }

    /**
     * Specifies whether a linear calibrator is used or not for preliminary
     * solutions.
     *
     * @param linearCalibratorUsed indicates whether a linear calibrator is used
     *                             or not for preliminary solutions.
     * @throws LockedException if calibrator is currently running.
     */
    public void setLinearCalibratorUsed(final boolean linearCalibratorUsed) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        useLinearCalibrator = linearCalibratorUsed;
    }

    /**
     * Indicates whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @return true if preliminary solutions must be refined after an initial linear solution, false
     * otherwise.
     */
    public boolean isPreliminarySolutionRefined() {
        return refinePreliminarySolutions;
    }

    /**
     * Specifies whether preliminary solutions must be refined after an initial linear solution is found.
     * If no initial solution is found using a linear solver, a non linear solver will be
     * used regardless of this value using an average solution as the initial value to be
     * refined.
     *
     * @param preliminarySolutionRefined true if preliminary solutions must be refined after an
     *                                   initial linear solution, false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPreliminarySolutionRefined(final boolean preliminarySolutionRefined) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        refinePreliminarySolutions = preliminarySolutionRefined;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return array containing x,y,z components of estimated accelerometer biases.
     */
    @Override
    public double[] getEstimatedBiases() {

super(groundTruthGravityNorm, measurements, commonAxisUsed, bias, initialMa, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples
     *                                  (10 or 13).
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether calibrator is ready to find a solution.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROSACRobustKnownBiasAndGravityNormAccelerometerCalibrator.this.isReady();

super(groundTruthGravityNorm, measurements, commonAxisUsed, bias, initialMa, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples
     *                                  (10 or 13).
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether calibrator is ready to find a solution.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROSACRobustKnownBiasAndGravityNormAccelerometerCalibrator.this.isReady();

estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                listener, DEFAULT_ROBUST_METHOD);
    }


    /**
     * Computes error of a preliminary result respect a given measurement.
     *
     * @param measurement       a measurement.
     * @param preliminaryResult a preliminary result.
     * @return computed error.
     */
    protected double computeError(
            final StandardDeviationBodyKinematics measurement, final PreliminaryResult preliminaryResult) {
        // We know that measured angular rate is:
        // Ωmeas = bg + (I + Mg) * Ωtrue + Gg * ftrue

        // Hence:
        // [Ωmeasx] = [bx] + ( [1   0   0] + [sx    mxy    mxz]) [Ωtruex] + [g11   g12   g13][ftruex]
        // [Ωmeasy]   [by]     [0   1   0]   [myx   sy     myz]  [Ωtruey]   [g21   g22   g23][ftruey]
        // [Ωmeasz]   [bz]     [0   0   1]   [mzx   mzy    sz ]  [Ωtruez]   [g31   g32   g33][ftruez]

        final var measuredKinematics = measurement.getKinematics();

        final var specificForce = new double[]{
                measuredKinematics.getFx(),
                measuredKinematics.getFy(),
                measuredKinematics.getFz()
        };

        try {
            final var axis1 = ArrayUtils.normalizeAndReturnNew(specificForce);
            final var rot1 = new Quaternion(axis1, 0.0);

            final var nedC1 = new CoordinateTransformation(
                    rot1.asInhomogeneousMatrix(), FrameType.BODY_FRAME, FrameType.LOCAL_NAVIGATION_FRAME);

            final var nedPosition = getNedPosition();
            final var nedFrame1 = new NEDFrame(nedPosition, nedC1);
            final var ecefFrame1 = NEDtoECEFFrameConverter.convertNEDtoECEFAndReturnNew(nedFrame1);
            var ti = this.timeInterval;
            var angleIncrement = turntableRotationRate * ti;
            if (Math.abs(angleIncrement) > Math.PI / 2.0) {
                // angle = rot_rate * interval
                // rot_rate * interval / x = angle / x

                // if we want angle / x = pi / 2, then:
                final var x = Math.abs(angleIncrement) / (Math.PI / 2.0);
                ti /= x;
                angleIncrement = turntableRotationRate * ti;
            }
            final var rot = new AxisRotation3D(axis1, angleIncrement);
            final var rot2 = rot1.combineAndReturnNew(rot);
            final var nedC2 = new CoordinateTransformation(rot2.asInhomogeneousMatrix(), FrameType.BODY_FRAME,
                    FrameType.LOCAL_NAVIGATION_FRAME);

            final var nedFrame2 = new NEDFrame(nedPosition, nedC2);
            final var ecefFrame2 = NEDtoECEFFrameConverter.convertNEDtoECEFAndReturnNew(nedFrame2);

            final var expectedKinematics = ECEFKinematicsEstimator.estimateKinematicsAndReturnNew(ti,
                    ecefFrame2, ecefFrame1);

            final var angularRateMeasX1 = measuredKinematics.getAngularRateX();
            final var angularRateMeasY1 = measuredKinematics.getAngularRateY();
            final var angularRateMeasZ1 = measuredKinematics.getAngularRateZ();

            final var angularRateTrueX = expectedKinematics.getAngularRateX();
            final var angularRateTrueY = expectedKinematics.getAngularRateY();
            final var angularRateTrueZ = expectedKinematics.getAngularRateZ();

            final var fTrueX = expectedKinematics.getFx();
            final var fTrueY = expectedKinematics.getFy();
            final var fTrueZ = expectedKinematics.getFz();

            final var mg = preliminaryResult.estimatedMg;

for (final var sequence : sequences) {
            fixedSequences.add(new BodyKinematicsSequence<>(sequence));
        }

        accelerationFixer.setBias(ba);
        accelerationFixer.setCrossCouplingErrors(ma);

        var i = 0;
        for (final var sequence : sequences) {
            // sequence mean accelerometer samples of previous static
            // period will need to be fixed using accelerometer calibration
            // parameters
            measuredBeforeF[0] = sequence.getBeforeMeanFx();
            measuredBeforeF[1] = sequence.getBeforeMeanFy();
            measuredBeforeF[2] = sequence.getBeforeMeanFz();
            accelerationFixer.fix(measuredBeforeF, fixedBeforeF);

            measuredAfterF[0] = sequence.getAfterMeanFx();
            measuredAfterF[1] = sequence.getAfterMeanFy();
            measuredAfterF[2] = sequence.getAfterMeanFz();
            accelerationFixer.fix(measuredAfterF, fixedAfterF);

            // because we are only interested in gravity direction, we
            // normalize these vectors, so that gravity becomes independent
            // of current Earth position.
            ArrayUtils.normalize(fixedBeforeF);
            ArrayUtils.normalize(fixedAfterF);

            x.setSubmatrix(i, 0, i, 2, fixedBeforeF);
            x.setSubmatrix(i, 3, i, 5, fixedAfterF);

            y[i] = 0.0;

            standardDeviations[i] = computeAverageAngularRateStandardDeviation(sequence);
            i++;
        }

        fitter.setInputData(x, y, standardDeviations);
    }

    /**
     * Computes average angular rate standard deviation for measurements
     * in provided sequence.
     *
     * @param sequence a sequence.
     * @return average angular rate standard deviation expressed in radians
     * per second (rad/s).
     */
    private static double computeAverageAngularRateStandardDeviation(
            final BodyKinematicsSequence<StandardDeviationTimedBodyKinematics> sequence) {
        final var items = sequence.getSortedItems();
        final var size = items.size();

        var result = 0.0;
        for (final var item : items) {
            result += item.getAngularRateStandardDeviation() / size;
        }

        return result;
    }

    /**
     * Converts acceleration instance to meters per squared second.
     *
     * @param acceleration acceleration instance to be converted.
     * @return converted value.
     */
    private static double convertAcceleration(final Acceleration acceleration) {
        return AccelerationConverter.convert(acceleration.getValue().doubleValue(), acceleration.getUnit(),
                AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Converts angular speed value and unit to radians per second.
     *
     * @param value angular speed value.
     * @param unit  unit of angular speed value.
     * @return converted value.
     */
    private static double convertAngularSpeed(final double value, final AngularSpeedUnit unit) {
        return AngularSpeedConverter.convert(value, unit, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Converts angular speed instance to radians per second.
     *
     * @param angularSpeed angular speed instance to be converted.
     * @return converted value.
     */
    private static double convertAngularSpeed(final AngularSpeed angularSpeed) {
        return convertAngularSpeed(angularSpeed.getValue().doubleValue(), angularSpeed.getUnit());
    }

    /**
     * Makes proper conversion of internal cross-coupling, bias and g-dependent
     * cross bias matrices.
     *
     * @param m internal scaling and cross-coupling matrix.
     * @param b internal bias matrix.
     * @param g internal g-dependent cross bias matrix.
     * @throws AlgebraException if a numerical instability occurs.
     */
    private void setResult(final Matrix m, final Matrix b, final Matrix g) throws AlgebraException {

public void setListener(final RobustKnownBiasAndGravityNormAccelerometerCalibratorListener listener)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurements() {
        return commonAxisUsed ? MINIMUM_MEASUREMENTS_COMMON_Z_AXIS : MINIMUM_MEASUREMENTS_GENERAL;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= getMinimumRequiredMeasurements()
                && groundTruthGravityNorm != null;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {

public void setListener(final RobustKnownBiasAndPositionAccelerometerCalibratorListener listener)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurements() {
        return commonAxisUsed ? MINIMUM_MEASUREMENTS_COMMON_Z_AXIS : MINIMUM_MEASUREMENTS_GENERAL;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= getMinimumRequiredMeasurements() && position != null;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {

public void setListener(final RobustKnownHardIronMagneticFluxDensityNormMagnetometerCalibratorListener listener)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurements() {
        return commonAxisUsed ? MINIMUM_MEASUREMENTS_COMMON_Z_AXIS : MINIMUM_MEASUREMENTS_GENERAL;
    }

    /**
     * Indicates whether calibrator is ready to start the estimator.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= getMinimumRequiredMeasurements()
                && groundTruthMagneticFluxDensityNorm != null;
    }

    /**
     * Indicates whether calibrator is currently running or no.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {

setResult(crossCoupling, bias);

        // at this point covariance is expressed in terms of b and M, and must
        // be expressed in terms of ba and Ma.
        // We know that:

        // b = [bx]
        //     [by]
        //     [bz]

        // M = [m11 	m12 	m13]
        //     [m21 	m22 	m23]
        //     [m31 	m32 	m33]

        // and that ba and Ma are expressed as:
        // Ma = M - I
        // ba = M * b

        // Ma = [m11 - 1    m12         m13    ] =  [sx     mxy     mxz]
        //      [m21        m22 - 1     m23    ]    [myx    sy      myz]
        //      [m31        m32         m33 - 1]    [mzx    mzy     sz ]

        // ba = [m11 * bx + m12 * by + m13 * bz] = 	[bax]
        //      [m21 * bx + m22 * by + m23 * bz]	[bay]
        //      [m31 * bx + m32 * by + m33 * bz]	[baz]

        // Defining the linear application:
        // F(b, M) = F(bx, by, bz, m11, m21, m31, m12, m22, m32, m13, m23, m33)
        // as:
        // [bax] = 	[m11 * bx + m12 * by + m13 * bz]
        // [bay]	[m21 * bx + m22 * by + m23 * bz]
        // [baz]	[m31 * bx + m32 * by + m33 * bz]
        // [sx]		[m11 - 1]
        // [sy]		[m22 - 1]
        // [sz]		[m33 - 1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [m21]
        // [myz]    [m23]
        // [mzx]    [m31]
        // [mzy]    [m32]

        // Then the Jacobian of F(b, M) is:
        // J = 	[m11  m12  m13  bx  0   0   by  0   0   bz  0   0 ]
        //	    [m21  m22  m23  0   bx  0   0   by  0   0   bz  0 ]
        //	    [m31  m32  m33  0   0   bx  0   0   by  0   0   bz]
        //	    [0    0    0    1   0   0   0   0   0   0   0   0 ]
        //	    [0    0    0    0   0   0   0   1   0   0   0   0 ]
        //	    [0    0    0    0   0   0   0   0   0   0   0   1 ]
        //	    [0    0    0    0   0   0   1   0   0   0   0   0 ]
        //	    [0    0    0    0   0   0   0   0   0   1   0   0 ]
        //	    [0    0    0    0   1   0   0   0   0   0   0   0 ]
        //	    [0    0    0    0   0   0   0   0   0   0   1   0 ]
        //	    [0    0    0    0   0   1   0   0   0   0   0   0 ]
        //	    [0    0    0    0   0   0   0   0   1   0   0   0 ]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS, GENERAL_UNKNOWNS);

        jacobian.setElementAt(0, 0, m11);
        jacobian.setElementAt(1, 0, m21);
        jacobian.setElementAt(2, 0, m31);

        jacobian.setElementAt(0, 1, m12);
        jacobian.setElementAt(1, 1, m22);
        jacobian.setElementAt(2, 1, m32);

        jacobian.setElementAt(0, 2, m13);
        jacobian.setElementAt(1, 2, m23);
        jacobian.setElementAt(2, 2, m33);

        jacobian.setElementAt(0, 3, bx);
        jacobian.setElementAt(3, 3, 1.0);

        jacobian.setElementAt(1, 4, bx);
        jacobian.setElementAt(8, 4, 1.0);

        jacobian.setElementAt(2, 5, bx);
        jacobian.setElementAt(10, 5, 1.0);

        jacobian.setElementAt(0, 6, by);
        jacobian.setElementAt(6, 6, 1.0);

        jacobian.setElementAt(1, 7, by);
        jacobian.setElementAt(4, 7, 1.0);

        jacobian.setElementAt(2, 8, by);
        jacobian.setElementAt(11, 8, 1.0);

        jacobian.setElementAt(0, 9, bz);
        jacobian.setElementAt(7, 9, 1.0);

        jacobian.setElementAt(1, 10, bz);
        jacobian.setElementAt(9, 10, 1.0);

        jacobian.setElementAt(2, 11, bz);
        jacobian.setElementAt(5, 11, 1.0);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed for both
     * the accelerometer and gyroscope.
     *
     * @throws FittingException                         if Levenberg-Marquardt fails for numerical reasons.
     * @throws AlgebraException                         if there are numerical instabilities that prevent
     *                                                  matrix inversion.
     * @throws com.irurueta.numerical.NotReadyException never happens.
     */
    private void calibrateCommonAxis() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {
        // The accelerometer model is:
        // fmeas = ba + (I + Ma) * ftrue + w

        // Ideally a least squares solution tries to minimize noise component, so:
        // fmeas = ba + (I + Ma) * ftrue

        // For convergence purposes of the Levenberg-Marquardt algorithm, the
        // accelerometer model can be better expressed as:
        // fmeas = T*K*(ftrue + b)
        // fmeas = M*(ftrue + b)
        // fmeas = M*ftrue + M*b

        // where:
        // M = I + Ma
        // ba = M*b = (I + Ma)*b --> b = M^-1*ba

        // We know that the norm of the true specific force is equal to the amount
        // of gravity at a certain Earth position
        // ||ftrue|| = ||g|| ~ 9.81 m/s^2

        // Hence:
        // fmeas - M*b = M*ftrue

        // M^-1 * (fmeas - M*b) = ftrue

        // ||g||^2 = ||ftrue||^2 = (M^-1 * (fmeas - M*b))^T * (M^-1 * (fmeas - M*b))
        // ||g||^2 = (fmeas - M*b)^T*(M^-1)^T * M^-1 * (fmeas - M*b)
        // ||g||^2 = (fmeas - M * b)^T * ||M^-1||^2 * (fmeas - M * b)
        // ||g||^2 = ||fmeas - M * b||^2 * ||M^-1||^2

        // Where:

        // b = [bx]
        //     [by]
        //     [bz]

        // M = [m11 	m12 	m13]
        //     [0 		m22 	m23]
        //     [0 	 	0 		m33]


        final var gradientEstimator = new GradientEstimator(this::evaluateCommonAxis);

        final var initialM = Matrix.identity(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);

estimatedMa.setElementAt(i, i, estimatedMa.getElementAt(i, i) - 1.0);
        }

        estimatedCovariance = fitter.getCovar();
        estimatedChiSq = fitter.getChisq();
        estimatedMse = fitter.getMse();
    }

    /**
     * Computes estimated true specific force squared norm using current measured
     * specific force and provided parameters for the general case.
     * This method is internally executed during gradient estimation and
     * Levenberg-Marquardt fitting needed for calibration computation.
     *
     * @param params array containing current parameters for the general purpose case.
     *               Must have length 12.
     * @return estimated true specific force squared norm.
     * @throws EvaluationException if there are numerical instabilities.
     */
    private double evaluateGeneral(final double[] params) throws EvaluationException {
        final var bx = params[0];
        final var by = params[1];
        final var bz = params[2];

        final var m11 = params[3];
        final var m21 = params[4];
        final var m31 = params[5];

        final var m12 = params[6];
        final var m22 = params[7];
        final var m32 = params[8];

        final var m13 = params[9];
        final var m23 = params[10];
        final var m33 = params[11];

        return evaluate(bx, by, bz, m11, m21, m31, m12, m22, m32, m13, m23, m33);
    }

    /**
     * Computes estimated true specific force squared norm using current measured
     * specific force and provided parameters when common z-axis is assumed.
     * This method is internally executed during gradient estimation and
     * Levenberg-Marquardt fitting needed for calibration computation.
     *
     * @param params array containing current parameters for the common z-axis case.
     *               Must have length 9.
     * @return estimated true specific force squared norm.
     * @throws EvaluationException if there are numerical instabilities.
     */
    private double evaluateCommonAxis(final double[] params) throws EvaluationException {
        final var bx = params[0];
        final var by = params[1];
        final var bz = params[2];

        final var m11 = params[3];

        final var m12 = params[4];
        final var m22 = params[5];

        final var m13 = params[6];
        final var m23 = params[7];
        final var m33 = params[8];

        return evaluate(bx, by, bz, m11, 0.0, 0.0, m12, m22, 0.0, m13, m23, m33);
    }

    /**
     * Computes estimated true specific force squared norm using current measured
     * specific force and provided parameters.
     * This method is internally executed during gradient estimation and
     * Levenberg-Marquardt fitting needed for calibration computation.
     *
     * @param bx  x-coordinate of bias.
     * @param by  y-coordinate of bias.
     * @param bz  z-coordinate of bias.
     * @param m11 element 1,1 of cross-coupling error matrix.
     * @param m21 element 2,1 of cross-coupling error matrix.
     * @param m31 element 3,1 of cross-coupling error matrix.
     * @param m12 element 1,2 of cross-coupling error matrix.
     * @param m22 element 2,2 of cross-coupling error matrix.
     * @param m32 element 3,2 of cross-coupling error matrix.
     * @param m13 element 1,3 of cross-coupling error matrix.
     * @param m23 element 2,3 of cross-coupling error matrix.
     * @param m33 element 3,3 of cross-coupling error matrix.
     * @return estimated true specific force squared norm.
     * @throws EvaluationException if there are numerical instabilities.
     */
    private double evaluate(final double bx, final double by, final double bz,
                            final double m11, final double m21, final double m31,
                            final double m12, final double m22, final double m32,
                            final double m13, final double m23, final double m33) throws EvaluationException {

        // fmeas = M*(ftrue + b)

        // ftrue = M^-1*fmeas - b

        try {
            if (fmeas == null) {

setInitialCrossCouplingErrors(initialMxy, initialMxz, initialMyx, initialMyz, initialMzx, initialMzy);
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets known bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param bias known bias to be set
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (bias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        biasX = bias[0];
        biasY = bias[1];
        biasZ = bias[2];
    }

    /**
     * Gets known bias as a column matrix.
     *
     * @return known bias as a column matrix.
     */
    @Override
    public Matrix getBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, biasX);
        result.setElementAtIndex(1, biasY);
        result.setElementAtIndex(2, biasZ);
    }

    /**
     * Sets known bias as an array.
     *
     * @param bias bias to be set.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setBias(final Matrix bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (bias.getRows() != BodyKinematics.COMPONENTS || bias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        biasX = bias.getElementAtIndex(0);
        biasY = bias.getElementAtIndex(1);
        biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {

estimateKinematics(timeInterval, c, oldC, velocity, oldVelocity, position, result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            boy-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param position     body position expressed in meters (m) with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public void estimate(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final Speed vx, final Speed vy, final Speed vz, final Speed oldVx, final Speed oldVy, final Speed oldVz,
            final Point3D position, final BodyKinematics result) {
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz, position, result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs.
     * @param c            boy-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param position     body position expressed in meters (m) with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public void estimate(
            final Time timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final Speed vx, final Speed vy, final Speed vz, final Speed oldVx, final Speed oldVy, final Speed oldVz,
            final Point3D position, final BodyKinematics result) {
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz, position, result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @return a new body kinematics instance.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public BodyKinematics estimateAndReturnNew(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final double vx, final double vy, final double vz,
            final double oldVx, final double oldVy, final double oldVz,
            final double x, final double y, final double z) {
        return estimateKinematicsAndReturnNew(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz, x, y, z);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between.
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @return a new body kinematics instance.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public BodyKinematics estimateAndReturnNew(
            final Time timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final double vx, final double vy, final double vz,
            final double oldVx, final double oldVy, final double oldVz,
            final double x, final double y, final double z) {
        return estimateKinematicsAndReturnNew(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz, x, y, z);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            boy-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param velocity     velocity of body frame with respect ECEF frame.
     * @param oldVelocity  previous velocity of body frame with respect ECEF frame.
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @return a new body kinematics instance.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public BodyKinematics estimateAndReturnNew(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,

}

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getHardIron() {
        final var result = new double[BodyMagneticFluxDensity.COMPONENTS];
        getHardIron(result);
        return result;
    }

    /**
     * Gets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have
     *                                  length 3.
     */
    @Override
    public void getHardIron(final double[] result) {
        if (result.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = hardIronX;
        result[1] = hardIronY;
        result[2] = hardIronZ;
    }

    /**
     * Sets known hard-iron bias as an array.
     * Array values are expressed in Teslas (T).
     *
     * @param hardIron known hard-iron.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setHardIron(final double[] hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (hardIron.length != BodyMagneticFluxDensity.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        hardIronX = hardIron[0];
        hardIronY = hardIron[1];
        hardIronZ = hardIron[2];
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @return known hard-iron bias as a column matrix.
     */
    @Override
    public Matrix getHardIronMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, 1);
            getHardIronMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known hard-iron bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getHardIronMatrix(final Matrix result) {
        if (result.getRows() != BodyMagneticFluxDensity.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, hardIronX);
        result.setElementAtIndex(1, hardIronY);
        result.setElementAtIndex(2, hardIronZ);
    }

    /**
     * Sets known hard-iron bias as a column matrix.
     *
     * @param hardIron known hard-iron bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setHardIron(final Matrix hardIron) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (hardIron.getRows() != BodyMagneticFluxDensity.COMPONENTS || hardIron.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        hardIronX = hardIron.getElementAtIndex(0);
        hardIronY = hardIron.getElementAtIndex(1);
        hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {

final var result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @return initial gyroscope bias to be used to find a solution as a
     * column matrix.
     */
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * a column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial gyroscope bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @return initial bias coordinates.
     */
    public AngularSpeedTriad getInitialBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    public void getInitialBiasAsTriad(AngularSpeedTriad result) {

final double[] result = new double[BodyKinematics.COMPONENTS];
        getInitialBias(result);
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void getInitialBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = initialBiasX;
        result[1] = initialBiasY;
        result[2] = initialBiasZ;
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * an array.
     * Array values are expressed in radians per second (rad/s).
     *
     * @param initialBias initial bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    public void setInitialBias(final double[] initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (initialBias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        initialBiasX = initialBias[0];
        initialBiasY = initialBias[1];
        initialBiasZ = initialBias[2];
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @return initial gyroscope bias to be used to find a solution as a
     * column matrix.
     */
    public Matrix getInitialBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getInitialBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial gyroscope bias to be used to find a solution as a
     * column matrix.
     * Values are expressed in radians per second (rad/s).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void getInitialBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialBiasX);
        result.setElementAtIndex(1, initialBiasY);
        result.setElementAtIndex(2, initialBiasZ);
    }

    /**
     * Sets initial gyroscope bias to be used to find a solution as
     * a column matrix with values expressed in radians per second (rad/s).
     *
     * @param initialBias initial gyroscope bias to find a solution.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    public void setInitialBias(final Matrix initialBias) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialBias.getRows() != BodyKinematics.COMPONENTS || initialBias.getColumns() != 1) {
            throw new IllegalArgumentException();
        }

        initialBiasX = initialBias.getElementAtIndex(0);
        initialBiasY = initialBias.getElementAtIndex(1);
        initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @return initial bias coordinates.
     */
    public AngularSpeedTriad getInitialBiasAsTriad() {
        return new AngularSpeedTriad(AngularSpeedUnit.RADIANS_PER_SECOND, initialBiasX, initialBiasY, initialBiasZ);
    }

    /**
     * Gets initial bias coordinates of gyroscope used to find a solution.
     *
     * @param result instance where result will be stored.
     */
    public void getInitialBiasAsTriad(AngularSpeedTriad result) {

fillHardIronBiases(bx, by, bz);
        fillMm(sx, sy, sz, mxy, mxz, 0.0, myz, 0.0, 0.0);
    }

    /**
     * Internal method to perform general calibration.
     *
     * @throws AlgebraException if there are numerical errors.
     * @throws IOException      if world magnetic model cannot be loaded.
     */
    private void calibrateGeneral() throws AlgebraException, IOException {
        // The magnetometer model is:
        // mBmeas = bm + (I + Mm) * mBtrue + w

        // Ideally a least squares solution tries to minimize noise component, so:
        // mBmeas = bm + (I + Mm) * mBtrue

        // Hence:
        // [mBmeasx] = [bx] + ( [1  0   0] + [sx    mxy mxz])   [mBtruex]
        // [mBmeasy] = [by]     [0  1   0]   [myx   sy  myz]    [mBtruey]
        // [mBmeasz] = [bz]     [0  0   1]   [mzx   mzy sz ]    [mBtruez]

        // [mBmeasx] = [bx] +   [1+sx   mxy     mxz ][mBtruex]
        // [mBmeasy]   [by]     [myx    1+sy    myz ][mBtruey]
        // [mBmeasz]   [bz]     [mzx    mzy     1+sz][mBtruez]

        // mBmeasx = bx + (1+sx) * mBtruex + mxy * mBtruey + mxz * mBtruez
        // mBmeasy = by + myx * mBtruex + (1+sy) * mBtruey + myz * mBtruez
        // mBmeasz = bz + mzx * mBtruex + mzy * mBtruey + (1+sz) * mBtruez

        // Where the unknowns are: bx, by, bz, sx, sy, sz, mxy mxz, myx, myz, mzx, mzy
        // Reordering:
        // mBmeasx = bx + mBtruex + sx * mBtruex + mxy * mBtruey + mxz * mBtruez
        // mBmeasy = by + myx * mBtruex + mBtruey + sy * mBtruey + myz * mBtruez
        // mBmeasz = bz + mzx * mBtruex + mzy * mBtruey + mBtruez + sz * mBtruez

        // mBmeasx - mBtruex = bx + sx * mBtruex + mxy * mBtruey + mxz * mBtruez
        // mBmeasy - mBtruey = by + myx * mBtruex + sy * mBtruey + myz * mBtruez
        // mBmeasz - mBtruez = bz + mzx * mBtruex + mzy * mBtruey + sz * mBtruez

        // [1   0   0   mBtruex  0        0        mBtruey  mBtruez  0        0        0        0      ][bx ] = [mBmeasx - mBtruex]
        // [0   1   0   0        mBtruey  0        0        0        mBtruex  mBtruez  0        0      ][by ]   [mBmeasy - mBtruey]
        // [0   0   1   0        0        mBtruez  0        0        0        0        mBtruex  mBtruey][bz ]   [mBmeasz - mBtruez]
        //                                                                                              [sx ]
        //                                                                                              [sy ]
        //                                                                                              [sz ]
        //                                                                                              [mxy]
        //                                                                                              [mxz]
        //                                                                                              [myx]
        //                                                                                              [myz]
        //                                                                                              [mzx]
        //                                                                                              [mzy]

        final WMMEarthMagneticFluxDensityEstimator wmmEstimator;
        if (magneticModel != null) {
            wmmEstimator = new WMMEarthMagneticFluxDensityEstimator(magneticModel);
        } else {
            wmmEstimator = new WMMEarthMagneticFluxDensityEstimator();
        }

        final var expectedMagneticFluxDensity = new BodyMagneticFluxDensity();
        final var nedFrame = new NEDFrame();
        final var earthB = new NEDMagneticFluxDensity();
        final var cbn = new CoordinateTransformation(FrameType.BODY_FRAME, FrameType.LOCAL_NAVIGATION_FRAME);
        final var cnb = new CoordinateTransformation(FrameType.LOCAL_NAVIGATION_FRAME, FrameType.BODY_FRAME);

        final var rows = EQUATIONS_PER_MEASUREMENT * measurements.size();
        final var a = new Matrix(rows, GENERAL_UNKNOWNS);
        final var b = new Matrix(rows, 1);
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredMagneticFluxDensity = measurement.getMagneticFluxDensity();

            // estimate Earth magnetic flux density at frame position and
            // timestamp using WMM
            final var ecefFrame = measurement.getFrame();
            ECEFtoNEDFrameConverter.convertECEFtoNED(ecefFrame, nedFrame);

            final var year = measurement.getYear();

            final var latitude = nedFrame.getLatitude();
            final var longitude = nedFrame.getLongitude();
            final var height = nedFrame.getHeight();

            nedFrame.getCoordinateTransformation(cbn);
            cbn.inverse(cnb);

            wmmEstimator.estimate(latitude, longitude, height, year, earthB);

            // estimate expected body magnetic flux density taking into
            // account body attitude (inverse of frame orientation) and
            // estimated Earth magnetic flux density
            BodyMagneticFluxDensityEstimator.estimate(earthB, cnb, expectedMagneticFluxDensity);

            final var bMeasX = measuredMagneticFluxDensity.getBx();
            final var bMeasY = measuredMagneticFluxDensity.getBy();
            final var bMeasZ = measuredMagneticFluxDensity.getBz();

            final var bTrueX = expectedMagneticFluxDensity.getBx();
            final var bTrueY = expectedMagneticFluxDensity.getBy();
            final var bTrueZ = expectedMagneticFluxDensity.getBz();

            a.setElementAt(i, 0, 1.0);

super(sequences, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                accelerometerBias, accelerometerMa, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value, the
     * algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @return stop threshold to stop the algorithm prematurely when a certain
     * accuracy has been reached.
     */
    public double getStopThreshold() {
        return stopThreshold;
    }

    /**
     * Sets threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value,
     * the algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @param stopThreshold stop threshold to stop the algorithm prematurely
     *                      when a certain accuracy has been reached.
     * @throws IllegalArgumentException if provided value is zero or negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setStopThreshold(final double stopThreshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (stopThreshold <= MIN_STOP_THRESHOLD) {
            throw new IllegalArgumentException();
        }

        this.stopThreshold = stopThreshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == sequences.size();
    }

    /**
     * Estimates gyroscope calibration parameters containing bias, scale factors,
     * cross-coupling errors and G-dependent coupling.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROMedSRobustEstimator<>(
                new PROMedSRobustEstimatorListener<PreliminaryResult>() {
                    @Override
                    public double[] getQualityScores() {
                        return qualityScores;
                    }

                    @Override
                    public double getThreshold() {
                        return stopThreshold;
                    }

                    @Override
                    public int getTotalSamples() {
                        return sequences.size();
                    }

                    @Override
                    public int getSubsetSize() {
                        return preliminarySubsetSize;
                    }

                    @Override
                    public void estimatePreliminarSolutions(
                            final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                        computePreliminarySolutions(samplesIndices, solutions);
                    }

                    @Override
                    public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                        return computeError(sequences.get(i), currentEstimation);
                    }

                    @Override
                    public boolean isReady() {
                        return PROMedSRobustEasyGyroscopeCalibrator.this.isReady();

final boolean commonAxisUsed, final RobustKnownFrameGyroscopeCalibratorListener listener) {
        super(measurements, commonAxisUsed, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value, the
     * algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @return stop threshold to stop the algorithm prematurely when a certain
     * accuracy has been reached.
     */
    public double getStopThreshold() {
        return stopThreshold;
    }

    /**
     * Sets threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value,
     * the algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @param stopThreshold stop threshold to stop the algorithm prematurely
     *                      when a certain accuracy has been reached.
     * @throws IllegalArgumentException if provided value is zero or negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setStopThreshold(final double stopThreshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (stopThreshold <= MIN_STOP_THRESHOLD) {
            throw new IllegalArgumentException();
        }

        this.stopThreshold = stopThreshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Estimates accelerometer calibration parameters containing bias, scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROMedSRobustEstimator<>(
                new PROMedSRobustEstimatorListener<PreliminaryResult>() {
                    @Override
                    public double[] getQualityScores() {
                        return qualityScores;
                    }

                    @Override
                    public double getThreshold() {
                        return stopThreshold;
                    }

                    @Override
                    public int getTotalSamples() {
                        return measurements.size();
                    }

                    @Override
                    public int getSubsetSize() {
                        return preliminarySubsetSize;
                    }

                    @Override
                    public void estimatePreliminarSolutions(
                            final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                        computePreliminarySolutions(samplesIndices, solutions);
                    }

                    @Override
                    public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                        return computeError(measurements.get(i), currentEstimation);
                    }

                    @Override
                    public boolean isReady() {
                        return PROMedSRobustKnownFrameGyroscopeCalibrator.this.isReady();

super(position, measurements, commonAxisUsed, bias, initialMa, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value, the
     * algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @return stop threshold to stop the algorithm prematurely when a certain
     * accuracy has been reached.
     */
    public double getStopThreshold() {
        return stopThreshold;
    }

    /**
     * Sets threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value,
     * the algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @param stopThreshold stop threshold to stop the algorithm prematurely
     *                      when a certain accuracy has been reached.
     * @throws IllegalArgumentException if provided value is zero or negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setStopThreshold(final double stopThreshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (stopThreshold <= MIN_STOP_THRESHOLD) {
            throw new IllegalArgumentException();
        }

        this.stopThreshold = stopThreshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples
     *                                  (10 or 13).
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        gravityNorm = computeGravityNorm();

        final var innerEstimator = new PROMedSRobustEstimator<>(new PROMedSRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return stopThreshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROMedSRobustKnownBiasAndPositionAccelerometerCalibrator.this.isReady();

return evaluateGeneral(i, params);
            }
        });

        setInputData();

        fitter.fit();

        final var result = fitter.getA();

        final var m11 = result[0];
        final var m21 = result[1];
        final var m31 = result[2];

        final var m12 = result[3];
        final var m22 = result[4];
        final var m32 = result[5];

        final var m13 = result[6];
        final var m23 = result[7];
        final var m33 = result[8];

        final var mm = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        mm.setElementAtIndex(0, m11);
        mm.setElementAtIndex(1, m21);
        mm.setElementAtIndex(2, m31);

        mm.setElementAtIndex(3, m12);
        mm.setElementAtIndex(4, m22);
        mm.setElementAtIndex(5, m32);

        mm.setElementAtIndex(6, m13);
        mm.setElementAtIndex(7, m23);
        mm.setElementAtIndex(8, m33);

        setResult(mm);

        // at this point covariance is expressed in terms of M, and must
        // be expressed in terms of Mg.
        // We know that:
        // Mg = M - I
        // Gg = M * G

        // M = [m11  m12  m13]
        //     [m21  m22  m23]
        //     [m31  m32  m33]

        // G = [g11  g12  g13] = 0
        //     [g21  g22  g23]
        //     [g31  g32  g33]

        // Mg = [sx  mxy  mxz] = [m11 - 1    m12         m13     ]
        //      [myx sy	  myz]   [m21        m22 - 1     m23     ]
        //      [mzx mzy  sz ]   [m31        m32         m33 - 1 ]

        // Gg = [gg11  gg12  gg13] = [m11  m12  m13][g11  g12  g13]
        //      [gg21  gg22  gg23]   [m21  m22  m23][g21  g22  g23]
        //      [gg31  gg32  gg33]   [m31  m32  m33][g31  g32  g33]

        // Defining the linear application:
        // F(M) = F(m11, m21, m31, m12, m22, m32, m13, m23, m33)
        // as:
        // [sx] =   [m11 - 1]
        // [sy]     [m22 - 1]
        // [sz]     [m33 - 1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [m21]
        // [myz]    [m23]
        // [mzx]    [m31]
        // [mzy]    [m32]
        // [gg11]   [0]
        // [gg21]   [0]
        // [gg31]   [0]
        // [gg12]   [0]
        // [gg22]   [0]
        // [gg32]   [0]
        // [gg13]   [0]
        // [gg23]   [0]
        // [gg33]   [0]

        // Then the Jacobian of F(M) is:
        // J = [1    0    0    0    0    0    0    0    0]
        //     [0    0    0    0    1    0    0    0    0]
        //     [0    0    0    0    0    0    0    0    1]
        //     [0    0    0    1    0    0    0    0    0]
        //     [0    0    0    0    0    0    1    0    0]
        //     [0    1    0    0    0    0    0    0    0]
        //     [0    0    0    0    0    0    0    1    0]
        //     [0    0    1    0    0    0    0    0    0]
        //     [0    0    0    0    0    1    0    0    0]
        //     [0    0    0    0    0    0    0    0    0]
        //     [0    0    0    0    0    0    0    0    0]
        //     [0    0    0    0    0    0    0    0    0]
        //     [0    0    0    0    0    0    0    0    0]
        //     [0    0    0    0    0    0    0    0    0]
        //     [0    0    0    0    0    0    0    0    0]
        //     [0    0    0    0    0    0    0    0    0]
        //     [0    0    0    0    0    0    0    0    0]
        //     [0    0    0    0    0    0    0    0    0]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS_AND_CROSS_BIASES, GENERAL_UNKNOWNS);

        jacobian.setElementAt(0, 0, 1.0);
        jacobian.setElementAt(1, 4, 1.0);
        jacobian.setElementAt(2, 8, 1.0);

        jacobian.setElementAt(3, 3, 1.0);
        jacobian.setElementAt(4, 6, 1.0);
        jacobian.setElementAt(5, 1, 1.0);

        jacobian.setElementAt(6, 7, 1.0);
        jacobian.setElementAt(7, 2, 1.0);
        jacobian.setElementAt(8, 5, 1.9);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Sets input data into Levenberg-Marquardt fitter.
     *
     * @throws AlgebraException if there are numerical instabilities.
     */
    private void setInputData() throws AlgebraException {

return EasyGyroscopeCalibrator.MINIMUM_SEQUENCES_GENERAL;
            }
        }
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return sequences != null && sequences.size() >= getMinimumRequiredMeasurementsOrSequences();
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {

return KnownBiasTurntableGyroscopeCalibrator.MINIMUM_MEASUREMENTS_GENERAL;
            }
        }
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= getMinimumRequiredMeasurementsOrSequences();
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {

}

    /**
     * Fills scale factor and cross coupling error matrix with estimated values.
     *
     * @param sx  x scale factor
     * @param sy  y scale factor
     * @param sz  z scale factor
     * @param mxy x-y cross coupling
     * @param mxz x-z cross coupling
     * @param myx y-x cross coupling
     * @param myz y-z cross coupling
     * @param mzx z-x cross coupling
     * @param mzy z-y cross coupling
     * @throws WrongSizeException never happens.
     */
    private void fillMg(final double sx, final double sy, final double sz,
                        final double mxy, final double mxz, final double myx,
                        final double myz, final double mzx, final double mzy) throws WrongSizeException {
        if (estimatedMg == null) {
            estimatedMg = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        }

        estimatedMg.setElementAt(0, 0, sx);
        estimatedMg.setElementAt(1, 0, myx);
        estimatedMg.setElementAt(2, 0, mzx);

        estimatedMg.setElementAt(0, 1, mxy);
        estimatedMg.setElementAt(1, 1, sy);
        estimatedMg.setElementAt(2, 1, mzy);

        estimatedMg.setElementAt(0, 2, mxz);
        estimatedMg.setElementAt(1, 2, myz);
        estimatedMg.setElementAt(2, 2, sz);
    }

    /**
     * Fills G-dependant cross biases.
     *
     * @param g11 element 1,1 of G-dependant cross biases matrix.
     * @param g12 element 1,2 of G-dependant cross biases matrix.
     * @param g13 element 1,3 of G-dependant cross biases matrix.
     * @param g21 element 2,1 of G-dependant cross biases matrix.
     * @param g22 element 2,2 of G-dependant cross biases matrix.
     * @param g23 element 2,3 of G-dependant cross biases matrix.
     * @param g31 element 3,1 of G-dependant cross biases matrix.
     * @param g32 element 3,2 of G-dependant cross biases matrix.
     * @param g33 element 3,3 of G-dependant cross biases matrix.
     * @throws WrongSizeException never happens.
     */
    private void fillGg(final double g11, final double g12, final double g13,
                        final double g21, final double g22, final double g23,
                        final double g31, final double g32, final double g33) throws WrongSizeException {
        if (estimatedGg == null) {
            estimatedGg = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        }

        estimatedGg.setElementAt(0, 0, g11);
        estimatedGg.setElementAt(0, 1, g12);
        estimatedGg.setElementAt(0, 2, g13);

        estimatedGg.setElementAt(1, 0, g21);
        estimatedGg.setElementAt(1, 1, g22);
        estimatedGg.setElementAt(1, 2, g23);

        estimatedGg.setElementAt(2, 0, g31);
        estimatedGg.setElementAt(2, 1, g32);
        estimatedGg.setElementAt(2, 2, g33);
    }

setResult(m, b);

        // at this point covariance is expressed in terms of b, M and G, and must
        // be expressed in terms of bg, Mg and Gg.
        // We know that:
        // bg = M * b
        // Mg = M - I
        // Gg = M * G = 0

        // b = [bx]
        //     [by]
        //     [bz]

        // M = [m11  m12  m13]
        //     [m21  m22  m23]
        //     [m31  m32  m33]

        // G = [g11  g12  g13] = 0
        //     [g21  g22  g23]
        //     [g31  g32  g33]

        // bg = [m11  m12  m13][bx] = [m11 * bx + m12 * by + m13 * bz] = [bgx]
        //      [m21  m22  m23][by]   [m21 * bx + m22 * by + m23 * bz]   [bgy]
        //      [m31  m32  m33][bz]   [m31 * bx + m32 * by + m33 * bz]   [bgz]

        // Mg = [sx  mxy  mxz] = [m11 - 1    m12         m13     ]
        //      [myx sy	  myz]   [m21        m22 - 1     m23     ]
        //      [mzx mzy  sz ]   [m31        m32         m33 - 1 ]

        // Gg = [gg11  gg12  gg13] = 0
        //      [gg21  gg22  gg23]
        //      [gg31  gg32  gg33]

        // Defining the linear application:
        // F(b, M) = F(bx, by, bz, m11, m21, m31, m12, m22, m32, m13, m23, m33)
        // as:
        // [bgx] =  [m11 * bx + m12 * by + m13 * bz]
        // [bgy]    [m21 * bx + m22 * by + m23 * bz]
        // [bgz]    [m31 * bx + m32 * by + m33 * bz]
        // [sx]     [m11 - 1]
        // [sy]     [m22 - 1]
        // [sz]     [m33 - 1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [m21]
        // [myz]    [m23]
        // [mzx]    [m31]
        // [mzy]    [m32]
        // [gg11]   [0]
        // [gg21]   [0]
        // [gg31]   [0]
        // [gg12]   [0]
        // [gg22]   [0]
        // [gg32]   [0]
        // [gg13]   [0]
        // [gg23]   [0]
        // [gg33]   [0]

        // Then the Jacobian of F(b, M) is:
        // J = [m11  m12  m13  bx   0    0    by   0    0    bz   0    0 ]
        //     [m21  m22  m23  0    bx   0    0    by   0    0    bz   0 ]
        //     [m31  m32  m33  0    0    bx   0    0    by   0    0    bz]
        //     [0    0    0    1    0    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    1    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    1 ]
        //     [0    0    0    0    0    0    1    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    1    0    0 ]
        //     [0    0    0    0    1    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    1    0 ]
        //     [0    0    0    0    0    1    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    1    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0 ]
        //     [0    0    0    0    0    0    0    0    0    0    0    0 ]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS_AND_CROSS_BIASES, GENERAL_UNKNOWNS);

        jacobian.setElementAt(0, 0, m11);
        jacobian.setElementAt(0, 1, m12);
        jacobian.setElementAt(0, 2, m13);
        jacobian.setElementAt(0, 3, bx);
        jacobian.setElementAt(0, 6, by);
        jacobian.setElementAt(0, 9, bz);

        jacobian.setElementAt(1, 0, m21);
        jacobian.setElementAt(1, 1, m22);
        jacobian.setElementAt(1, 2, m23);
        jacobian.setElementAt(1, 4, bx);
        jacobian.setElementAt(1, 7, by);
        jacobian.setElementAt(1, 10, bz);

        jacobian.setElementAt(2, 0, m31);
        jacobian.setElementAt(2, 1, m32);
        jacobian.setElementAt(2, 2, m33);
        jacobian.setElementAt(2, 5, bx);
        jacobian.setElementAt(2, 8, by);
        jacobian.setElementAt(2, 11, bz);

        jacobian.setElementAt(3, 3, 1.0);
        jacobian.setElementAt(4, 7, 1.0);
        jacobian.setElementAt(5, 11, 1.0);

        jacobian.setElementAt(6, 6, 1.0);
        jacobian.setElementAt(7, 9, 1.0);
        jacobian.setElementAt(8, 4, 1.0);

        jacobian.setElementAt(9, 10, 1.0);
        jacobian.setElementAt(10, 5, 1.0);
        jacobian.setElementAt(11, 8, 1.9);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Sets input data into Levenberg-Marquardt fitter.
     *
     * @throws AlgebraException if there are numerical instabilities.
     */
    private void setInputData() throws AlgebraException {

estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value, the
     * algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @return stop threshold to stop the algorithm prematurely when a certain
     * accuracy has been reached.
     */
    public double getStopThreshold() {
        return stopThreshold;
    }

    /**
     * Sets threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value,
     * the algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @param stopThreshold stop threshold to stop the algorithm prematurely
     *                      when a certain accuracy has been reached.
     * @throws IllegalArgumentException if provided value is zero or negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setStopThreshold(final double stopThreshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (stopThreshold <= MIN_STOP_THRESHOLD) {
            throw new IllegalArgumentException();
        }

        this.stopThreshold = stopThreshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Estimates gyroscope calibration parameters containing scale factors
     * cross-coupling errors and g-dependant cross biases.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROMedSRobustEstimator<>(
                new PROMedSRobustEstimatorListener<PreliminaryResult>() {
                    @Override
                    public double[] getQualityScores() {
                        return qualityScores;
                    }

                    @Override
                    public double getThreshold() {
                        return stopThreshold;
                    }

                    @Override
                    public int getTotalSamples() {
                        return measurements.size();
                    }

                    @Override
                    public int getSubsetSize() {
                        return preliminarySubsetSize;
                    }

                    @Override
                    public void estimatePreliminarSolutions(
                            final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                        computePreliminarySolutions(samplesIndices, solutions);
                    }

                    @Override
                    public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                        return computeError(measurements.get(i), currentEstimation);
                    }

                    @Override
                    public boolean isReady() {
                        return PROMedSRobustKnownBiasTurntableGyroscopeCalibrator.this.isReady();

super(groundTruthMagneticFluxDensityNorm, measurements, commonAxisUsed, initialHardIron, initialMm, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value, the
     * algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @return stop threshold to stop the algorithm prematurely when a certain
     * accuracy has been reached.
     */
    public double getStopThreshold() {
        return stopThreshold;
    }

    /**
     * Sets threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value,
     * the algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @param stopThreshold stop threshold to stop the algorithm prematurely
     *                      when a certain accuracy has been reached.
     * @throws IllegalArgumentException if provided value is zero or negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setStopThreshold(final double stopThreshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (stopThreshold <= MIN_STOP_THRESHOLD) {
            throw new IllegalArgumentException();
        }

        this.stopThreshold = stopThreshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Estimates magnetometer calibration parameters containing hard-iron
     * bias and soft-iron scale factors and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROMedSRobustEstimator<>(
                new PROMedSRobustEstimatorListener<PreliminaryResult>() {
                    @Override
                    public double[] getQualityScores() {
                        return qualityScores;
                    }

                    @Override
                    public double getThreshold() {
                        return stopThreshold;
                    }

                    @Override
                    public int getTotalSamples() {
                        return measurements.size();
                    }

                    @Override
                    public int getSubsetSize() {
                        return preliminarySubsetSize;
                    }

                    @Override
                    public void estimatePreliminarSolutions(
                            final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                        computePreliminarySolutions(samplesIndices, solutions);
                    }

                    @Override
                    public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                        return computeError(measurements.get(i), currentEstimation);
                    }

                    @Override
                    public boolean isReady() {
                        return PROMedSRobustKnownMagneticFluxDensityNormMagnetometerCalibrator.this.isReady();

final Time timeInterval, final ECEFFrame frame, final CoordinateTransformation oldC,
            final Speed oldVx, final Speed oldVy, final Speed oldVz, final BodyKinematics result) {
        estimateKinematics(timeInterval, frame, oldC,
                SpeedConverter.convert(oldVx.getValue().doubleValue(), oldVx.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVy.getValue().doubleValue(), oldVy.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVz.getValue().doubleValue(), oldVz.getUnit(), SpeedUnit.METERS_PER_SECOND),
                result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param position     body position expressed in meters (m) with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static void estimateKinematics(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final double vx, final double vy, final double vz,
            final double oldVx, final double oldVy, final double oldVz, final Point3D position,
            final BodyKinematics result) {
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz,
                position.getInhomX(), position.getInhomY(), position.getInhomZ(), result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs.
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes and expressed in meters per
     *                     second (m/s).
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes and expressed in meters
     *                     per second (m/s).
     * @param position     body position expressed in meters (m) with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static void estimateKinematics(
            final Time timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final double vx, final double vy, final double vz,
            final double oldVx, final double oldVy, final double oldVz, final Point3D position,
            final BodyKinematics result) {
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz,
                position.getInhomX(), position.getInhomY(), position.getInhomZ(), result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param velocity     velocity of body frame with respect ECEF frame.
     * @param oldVelocity  previous velocity of body frame with respect ECEF frame.
     * @param position     body position expressed in meters (m) with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static void estimateKinematics(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final ECEFVelocity velocity, final ECEFVelocity oldVelocity, final Point3D position,

this(measurements, bias, commonAxisUsed, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value, the
     * algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @return stop threshold to stop the algorithm prematurely when a certain
     * accuracy has been reached.
     */
    public double getStopThreshold() {
        return stopThreshold;
    }

    /**
     * Sets threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value,
     * the algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @param stopThreshold stop threshold to stop the algorithm prematurely
     *                      when a certain accuracy has been reached.
     * @throws IllegalArgumentException if provided value is zero or negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setStopThreshold(final double stopThreshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (stopThreshold <= MIN_STOP_THRESHOLD) {
            throw new IllegalArgumentException();
        }

        this.stopThreshold = stopThreshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROMedSRobustEstimator<>(new PROMedSRobustEstimatorListener<Matrix>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return stopThreshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(final int[] samplesIndices, final List<Matrix> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final Matrix currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROMedSRobustKnownBiasAndFrameAccelerometerCalibrator.this.isReady();

super(measurements, bias, commonAxisUsed, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value, the
     * algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @return stop threshold to stop the algorithm prematurely when a certain
     * accuracy has been reached.
     */
    public double getStopThreshold() {
        return stopThreshold;
    }

    /**
     * Sets threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value,
     * the algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @param stopThreshold stop threshold to stop the algorithm prematurely
     *                      when a certain accuracy has been reached.
     * @throws IllegalArgumentException if provided value is zero or negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setStopThreshold(final double stopThreshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (stopThreshold <= MIN_STOP_THRESHOLD) {
            throw new IllegalArgumentException();
        }

        this.stopThreshold = stopThreshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Estimates gyroscope calibration parameters containing bias, scale factors
     * cross-coupling errors and g-dependant cross biases.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROMedSRobustEstimator<>(
                new PROMedSRobustEstimatorListener<PreliminaryResult>() {
                    @Override
                    public double[] getQualityScores() {
                        return qualityScores;
                    }

                    @Override
                    public double getThreshold() {
                        return stopThreshold;
                    }

                    @Override
                    public int getTotalSamples() {
                        return measurements.size();
                    }

                    @Override
                    public int getSubsetSize() {
                        return preliminarySubsetSize;
                    }

                    @Override
                    public void estimatePreliminarSolutions(
                            final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                        computePreliminarySolutions(samplesIndices, solutions);
                    }

                    @Override
                    public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                        return computeError(measurements.get(i), currentEstimation);
                    }

                    @Override
                    public boolean isReady() {
                        return PROMedSRobustKnownBiasAndFrameGyroscopeCalibrator.this.isReady();

} catch (final FittingException | AlgebraException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32, gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed
     * for both the accelerometer and gyroscope and when G-dependent cross
     * biases are being estimated.
     *
     * @throws AlgebraException                         if accelerometer parameters prevent fixing
     *                                                  measured accelerometer values due to numerical instabilities.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateCommonAxisAndGDependentCrossBiases() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {

super(groundTruthGravityNorm, measurements, commonAxisUsed, bias, initialMa, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value, the
     * algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @return stop threshold to stop the algorithm prematurely when a certain
     * accuracy has been reached.
     */
    public double getStopThreshold() {
        return stopThreshold;
    }

    /**
     * Sets threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value,
     * the algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @param stopThreshold stop threshold to stop the algorithm prematurely
     *                      when a certain accuracy has been reached.
     * @throws IllegalArgumentException if provided value is zero or negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setStopThreshold(final double stopThreshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (stopThreshold <= MIN_STOP_THRESHOLD) {
            throw new IllegalArgumentException();
        }

        this.stopThreshold = stopThreshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples
     *                                  (10 or 13).
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROMedSRobustEstimator<>(new PROMedSRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return stopThreshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROMedSRobustKnownBiasAndGravityNormAccelerometerCalibrator.this.isReady();

super(groundTruthGravityNorm, measurements, commonAxisUsed, bias, initialMa, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Returns threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value, the
     * algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @return stop threshold to stop the algorithm prematurely when a certain
     * accuracy has been reached.
     */
    public double getStopThreshold() {
        return stopThreshold;
    }

    /**
     * Sets threshold to be used to keep the algorithm iterating in case that
     * best estimated threshold using median of residuals is not small enough.
     * Once a solution is found that generates a threshold below this value,
     * the algorithm will stop.
     * The stop threshold can be used to prevent the LMedS algorithm to iterate
     * too many times in cases where samples have a very similar accuracy.
     * For instance, in cases where proportion of outliers is very small (close
     * to 0%), and samples are very accurate (i.e. 1e-6), the algorithm would
     * iterate for a long time trying to find the best solution when indeed
     * there is no need to do that if a reasonable threshold has already been
     * reached.
     * Because of this behaviour the stop threshold can be set to a value much
     * lower than the one typically used in RANSAC, and yet the algorithm could
     * still produce even smaller thresholds in estimated results.
     *
     * @param stopThreshold stop threshold to stop the algorithm prematurely
     *                      when a certain accuracy has been reached.
     * @throws IllegalArgumentException if provided value is zero or negative.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setStopThreshold(final double stopThreshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (stopThreshold <= MIN_STOP_THRESHOLD) {
            throw new IllegalArgumentException();
        }

        this.stopThreshold = stopThreshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples
     *                                  (10 or 13).
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROMedSRobustEstimator<>(new PROMedSRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double[] getQualityScores() {
                return qualityScores;
            }

            @Override
            public double getThreshold() {
                return stopThreshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return PROMedSRobustKnownBiasAndGravityNormAccelerometerCalibrator.this.isReady();

} catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing g-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated position.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32, gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated position.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed for both
     * the accelerometer and gyroscope.
     *
     * @throws AlgebraException                         if there are numerical errors.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateCommonAxis() throws AlgebraException, FittingException,

super(sequences, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                accelerometerBias, accelerometerMa, listener);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured angular rates and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured angular rates and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates gyroscope calibration parameters containing bias, scale factors,
     * cross-coupling errors and G-dependent coupling.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new RANSACRobustEstimator<>(new RANSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return sequences.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(sequences.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return RANSACRobustEasyGyroscopeCalibrator.super.isReady();

super(groundTruthMagneticFluxDensityNorm, measurements, commonAxisUsed, initialHardIron, initialMm, listener);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates magnetometer calibration parameters containing hard-iron
     * bias and soft-iron scale factors and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new RANSACRobustEstimator<>(new RANSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return RANSACRobustKnownMagneticFluxDensityNormMagnetometerCalibrator.super.isReady();

super(position, measurements, commonAxisUsed, bias, initialMa, listener);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        gravityNorm = computeGravityNorm();

        final var innerEstimator = new RANSACRobustEstimator<>(new RANSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return RANSACRobustKnownBiasAndPositionAccelerometerCalibrator.super.isReady();

listener.onCalibrateEnd((C) this);
            }

        } catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {
        return estimatedMa;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy.
     *
     * @return estimated covariance matrix for estimated calibration parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

angularRateFixer.setBias(preliminaryResult.estimatedBiases);
            angularRateFixer.setCrossCouplingErrors(preliminaryResult.estimatedMg);
            angularRateFixer.setGDependantCrossBias(preliminaryResult.estimatedGg);

            // copy measured sequence as it will be used to fix kinematics values
            // using preliminary gyroscope parameters
            final var fixedSequence = new BodyKinematicsSequence<>(sequence);

            // fix body kinematic measurements of provided sequence
            final var numItems = sequence.getItemsCount();
            final var measuredItems = sequence.getSortedItems();
            final var fixedItems = fixedSequence.getSortedItems();
            for (var j = 0; j < numItems; j++) {
                final var measuredItem = measuredItems.get(j);
                final var fixedItem = fixedItems.get(j);

                final var measuredKinematics = measuredItem.getKinematics();
                final var fixedKinematics = fixedItem.getKinematics();
                fixKinematics(measuredKinematics, fixedKinematics);
            }

            // integrate fixed sequence to obtain attitude change
            QuaternionIntegrator.integrateGyroSequence(fixedSequence, QuaternionStepIntegratorType.RUNGE_KUTTA, q);

            // fix before coordinates
            measuredSpecificForce[0] = sequence.getBeforeMeanFx();
            measuredSpecificForce[1] = sequence.getBeforeMeanFy();
            measuredSpecificForce[2] = sequence.getBeforeMeanFz();
            accelerationFixer.fix(measuredSpecificForce, fixedSpecificForce);

            // normalize coordinates
            ArrayUtils.normalize(fixedSpecificForce);

            // compute estimated normalized end coordinates
            startPoint.setCoordinates(fixedSpecificForce);
            q.inverse();
            q.rotate(startPoint, endPoint);

            // fix after coordinates
            measuredSpecificForce[0] = sequence.getAfterMeanFx();
            measuredSpecificForce[1] = sequence.getAfterMeanFy();
            measuredSpecificForce[2] = sequence.getAfterMeanFz();
            accelerationFixer.fix(measuredSpecificForce, fixedSpecificForce);

            // normalize coordinates
            ArrayUtils.normalize(fixedSpecificForce);

            expectedEndPoint.setCoordinates(fixedSpecificForce);

            // compare estimated normalized end coordinates with expected
            // ones
            return expectedEndPoint.distanceTo(endPoint);

        } catch (final AlgebraException | RotationException e) {
            return Double.MAX_VALUE;
        }
    }

    /**
     * Computes a preliminary solution for a subset of samples picked by a robust estimator.
     *
     * @param samplesIndices indices of samples picked by the robust estimator.
     * @param solutions      list where estimated preliminary solution will be stored.
     */
    protected void computePreliminarySolutions(
            final int[] samplesIndices, final List<PreliminaryResult> solutions) {
        final var seqs = new ArrayList<BodyKinematicsSequence<StandardDeviationTimedBodyKinematics>>();

        for (final var samplesIndex : samplesIndices) {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyKinematics> getMeasurements() {

initialBiasZ = initialBias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets a collection of body kinematics measurements taken at
     * a given position with different unknown orientations and containing
     * the standard deviations of accelerometer and gyroscope measurements.
     *
     * @return collection of body kinematics measurements at a known position
     * with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyKinematics> getMeasurements() {

hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a list of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public List<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {

hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets a list of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     * If a single device IMU needs to be calibrated, typically all measurements are
     * taken at the same position, with zero velocity and multiple orientations.
     * However, if we just want to calibrate a given IMU model (e.g. obtain
     * an average and less precise calibration for the IMU of a given phone model),
     * we could take measurements collected throughout the planet at multiple positions
     * while the phone remains static (e.g. while charging), hence each measurement
     * position will change, velocity will remain zero and orientation will be
     * typically constant at horizontal orientation while the phone remains on a
     * flat surface.
     *
     * @return a collection of body magnetic flux density measurements taken at different
     * frames (positions, orientations and velocities).
     */
    @Override
    public List<StandardDeviationFrameBodyMagneticFluxDensity> getMeasurements() {

this(convertPosition(position), measurements, commonAxisUsed, bias, initialMa, listener);
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * ECEF coordinates.
     *
     * @return position where body kinematics measures have been taken.
     */
    public ECEFPosition getEcefPosition() {
        return position;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * ECEF coordinates.
     *
     * @param position position where body kinematics measures have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final ECEFPosition position) throws LockedException {
        if (isRunning()) {
            throw new LockedException();
        }

        this.position = position;
        if (position != null) {
            final var gravity = ECEFGravityEstimator.estimateGravityAndReturnNew(
                    this.position.getX(), this.position.getY(), this.position.getZ());
            groundTruthGravityNorm = gravity.getNorm();
        } else {
            groundTruthGravityNorm = null;
        }
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @return position where body kinematics measures have been taken or null if
     * not available.
     */
    public NEDPosition getNedPosition() {
        final var result = new NEDPosition();
        return getNedPosition(result) ? result : null;
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @param result instance where result will be stored.
     * @return true if NED position could be computed, false otherwise.
     */
    public boolean getNedPosition(final NEDPosition result) {

        if (position != null) {
            final var velocity = new NEDVelocity();
            ECEFtoNEDPositionVelocityConverter.convertECEFtoNED(
                    position.getX(), position.getY(), position.getZ(),
                    0.0, 0.0, 0.0, result, velocity);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Sets position where body kinematics measures have been taken expressed in
     * NED coordinates.
     *
     * @param position position where body kinematics measures have been taken.
     * @throws LockedException if calibrator is currently running.
     */
    public void setPosition(final NEDPosition position) throws LockedException {
        setPosition(position != null ? convertPosition(position) : null);
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && position != null;
    }

    /**
     * Converts provided NED position expressed in terms of latitude, longitude and height respect
     * mean Earth surface, to position expressed in ECEF coordinates.
     *
     * @param position NED position to be converted.
     * @return converted position expressed in ECEF coordinates.
     */
    private static ECEFPosition convertPosition(final NEDPosition position) {
        final var velocity = new ECEFVelocity();
        final var result = new ECEFPosition();
        NEDtoECEFPositionVelocityConverter.convertNEDtoECEF(
                position.getLatitude(), position.getLongitude(), position.getHeight(),
                0.0, 0.0, 0.0, result, velocity);
        return result;
    }
}

estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                listener);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured angular rates and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured angular rates and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates gyroscope calibration parameters containing scale factors
     * cross-coupling errors and g-dependant cross biases.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new RANSACRobustEstimator<>(new RANSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return RANSACRobustKnownBiasTurntableGyroscopeCalibrator.super.isReady();

return sequences != null && sequences.size() >= getMinimumRequiredMeasurementsOrSequences();
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {

return sequences != null && sequences.size() >= getMinimumRequiredMeasurementsOrSequences();
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each sequence.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {

super(measurements, bias, commonAxisUsed, listener);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new RANSACRobustEstimator<>(new RANSACRobustEstimatorListener<Matrix>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(final int[] samplesIndices, final List<Matrix> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final Matrix currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return RANSACRobustKnownBiasAndFrameAccelerometerCalibrator.super.isReady();

super(groundTruthGravityNorm, measurements, commonAxisUsed, bias, initialMa, listener);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new RANSACRobustEstimator<>(new RANSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return RANSACRobustKnownBiasAndGravityNormAccelerometerCalibrator.super.isReady();

super(measurements, commonAxisUsed, listener);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing bias, scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new RANSACRobustEstimator<>(new RANSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return RANSACRobustKnownFrameAccelerometerCalibrator.super.isReady();

hardIronZ = hardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

initialHardIronZ = initialHardIron.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMm() {
        Matrix result;
        try {
            result = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            getInitialMm(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMm(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMm initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMm(final Matrix initialMm) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMm.getRows() != BodyKinematics.COMPONENTS || initialMm.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMm.getElementAtIndex(0);
        initialMyx = initialMm.getElementAtIndex(1);
        initialMzx = initialMm.getElementAtIndex(2);

        initialMxy = initialMm.getElementAtIndex(3);
        initialSy = initialMm.getElementAtIndex(4);
        initialMzy = initialMm.getElementAtIndex(5);

        initialMxz = initialMm.getElementAtIndex(6);
        initialMyz = initialMm.getElementAtIndex(7);
        initialSz = initialMm.getElementAtIndex(8);
    }

    /**
     * Gets collection of body magnetic flux density measurements taken
     * at a given position with different unknown orientations and containing the
     * standard deviation of magnetometer measurements.
     *
     * @return collection of body magnetic flux density measurements at
     * a known position and timestamp with unknown orientations.
     */
    @Override
    public Collection<StandardDeviationBodyMagneticFluxDensity> getMeasurements() {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets ground truth gravity norm to be expected at location where measurements have been made,
     * expressed in meter per squared second (m/s^2).
     *
     * @return ground truth gravity norm or null.
     */
    public Double getGroundTruthGravityNorm() {

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     * This is only taken into account if non-linear preliminary solutions are used.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

    /**
     * Gets position where body kinematics measures have been taken expressed in
     * ECEF coordinates.
     *
     * @return position where body kinematics measures have been taken.
     */
    public ECEFPosition getEcefPosition() {

} catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing g-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated position.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32, gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated position.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Internal method to perform calibration when common z-axis is assumed for both
     * the accelerometer and gyroscope.
     *
     * @throws AlgebraException                         if there are numerical errors.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateCommonAxis() throws AlgebraException, FittingException,

biasZ = bias.getElementAtIndex(2);
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @return initial scale factors and cross coupling errors matrix.
     */
    @Override
    public Matrix getInitialMa() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            getInitialMa(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets initial scale factors and cross coupling errors matrix.
     *
     * @param result instance where data will be stored.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     */
    @Override
    public void getInitialMa(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, initialSx);
        result.setElementAtIndex(1, initialMyx);
        result.setElementAtIndex(2, initialMzx);

        result.setElementAtIndex(3, initialMxy);
        result.setElementAtIndex(4, initialSy);
        result.setElementAtIndex(5, initialMzy);

        result.setElementAtIndex(6, initialMxz);
        result.setElementAtIndex(7, initialMyz);
        result.setElementAtIndex(8, initialSz);
    }

    /**
     * Sets initial scale factors and cross coupling errors matrix.
     *
     * @param initialMa initial scale factors and cross coupling errors matrix.
     * @throws IllegalArgumentException if provided matrix is not 3x3.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setInitialMa(final Matrix initialMa) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (initialMa.getRows() != BodyKinematics.COMPONENTS || initialMa.getColumns() != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }

        initialSx = initialMa.getElementAtIndex(0);
        initialMyx = initialMa.getElementAtIndex(1);
        initialMzx = initialMa.getElementAtIndex(2);

        initialMxy = initialMa.getElementAtIndex(3);
        initialSy = initialMa.getElementAtIndex(4);
        initialMzy = initialMa.getElementAtIndex(5);

        initialMxz = initialMa.getElementAtIndex(6);
        initialMyz = initialMa.getElementAtIndex(7);
        initialSz = initialMa.getElementAtIndex(8);
    }

}

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return array containing x,y,z components of estimated accelerometer biases.
     */
    @Override
    public double[] getEstimatedBiases() {

} catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy.
     *
     * @return estimated covariance matrix for estimated position.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

public int getMinimumRequiredMeasurements() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Estimates accelerometer calibration parameters containing bias, scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }

        if (!isReady()) {
            throw new NotReadyException();
        }

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            if (commonAxisUsed) {
                calibrateCommonAxis();
            } else {
                calibrateGeneral();
            }

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return array containing x,y,z components of estimated accelerometer biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where estimated accelerometer biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return column matrix containing x,y,z components of estimated accelerometer
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFx() {

}

    /**
     * Returns amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @return amount of progress variation before notifying a progress change during
     * calibration.
     */
    public float getProgressDelta() {
        return progressDelta;
    }

    /**
     * Sets amount of progress variation before notifying a progress change during
     * calibration.
     *
     * @param progressDelta amount of progress variation before notifying a progress
     *                      change during calibration.
     * @throws IllegalArgumentException if progress delta is less than zero or greater than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setProgressDelta(final float progressDelta) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (progressDelta < MIN_PROGRESS_DELTA || progressDelta > MAX_PROGRESS_DELTA) {
            throw new IllegalArgumentException();
        }
        this.progressDelta = progressDelta;
    }

    /**
     * Returns amount of confidence expressed as a value between 0.0 and 1.0
     * (which is equivalent to 100%). The amount of confidence indicates the probability
     * that the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @return amount of confidence as a value between 0.0 and 1.0.
     */
    public double getConfidence() {
        return confidence;
    }

    /**
     * Sets amount of confidence expressed as a value between 0.0 and 1.0 (which is
     * equivalent to 100%). The amount of confidence indicates the probability that
     * the estimated result is correct. Usually this value will be close to 1.0, but
     * not exactly 1.0.
     *
     * @param confidence confidence to be set as a value between 0.0 and 1.0.
     * @throws IllegalArgumentException if provided value is not between 0.0 and 1.0.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setConfidence(final double confidence) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (confidence < MIN_CONFIDENCE || confidence > MAX_CONFIDENCE) {
            throw new IllegalArgumentException();
        }
        this.confidence = confidence;
    }

    /**
     * Returns maximum allowed number of iterations. If maximum allowed number of
     * iterations is achieved without converging to a result when calling calibrate(),
     * a RobustEstimatorException will be raised.
     *
     * @return maximum allowed number of iterations.
     */
    public int getMaxIterations() {
        return maxIterations;
    }

    /**
     * Sets maximum allowed number of iterations. When the maximum number of iterations
     * is exceeded, result will not be available, however an approximate result will be
     * available for retrieval.
     *
     * @param maxIterations maximum allowed number of iterations to be set.
     * @throws IllegalArgumentException if provided value is less than 1.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setMaxIterations(final int maxIterations) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (maxIterations < MIN_ITERATIONS) {
            throw new IllegalArgumentException();
        }
        this.maxIterations = maxIterations;
    }

    /**
     * Gets data related to inliers found after estimation.
     *
     * @return data related to inliers found after estimation.
     */
    public InliersData getInliersData() {
        return inliersData;
    }

    /**
     * Indicates whether result must be refined using a non-linear solver over found inliers.
     *
     * @return true to refine result, false to simply use result found by robust estimator
     * without further refining.
     */
    public boolean isResultRefined() {
        return refineResult;
    }

    /**
     * Specifies whether result must be refined using a non-linear solver over found inliers.
     *
     * @param refineResult true to refine result, false to simply use result found by robust
     *                     estimator without further refining.
     * @throws LockedException if calibrator is currently running.
     */
    public void setResultRefined(final boolean refineResult) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.refineResult = refineResult;
    }

    /**
     * Indicates whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @return true if covariance must be kept after refining result, false otherwise.
     */
    public boolean isCovarianceKept() {
        return keepCovariance;
    }

    /**
     * Specifies whether covariance must be kept after refining result.
     * This setting is only taken into account if result is refined.
     *
     * @param keepCovariance true if covariance must be kept after refining result,
     *                       false otherwise.
     * @throws LockedException if calibrator is currently running.
     */
    public void setCovarianceKept(final boolean keepCovariance) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.keepCovariance = keepCovariance;
    }

    /**
     * Returns quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation always returns null.
     * Subclasses using quality scores must implement proper behavior.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return null;
    }

    /**
     * Sets quality scores corresponding to each measurement.
     * The larger the score value the better the quality of the sample.
     * This implementation makes no action.
     * Subclasses using quality scores must implement proper behaviour.
     *
     * @param qualityScores quality scores corresponding to each pair of
     *                      matched points.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {

return false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bgx, bgy, bgz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32,
     * gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

return evaluateCommonAxis(i, params);
            }
        });

        setInputData();

        fitter.fit();

        final var result = fitter.getA();

        final var m11 = result[0];

        final var m12 = result[1];
        final var m22 = result[2];

        final var m13 = result[3];
        final var m23 = result[4];
        final var m33 = result[5];

        final var mm = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        mm.setElementAtIndex(0, m11);
        mm.setElementAtIndex(1, 0.0);
        mm.setElementAtIndex(2, 0.0);

        mm.setElementAtIndex(3, m12);
        mm.setElementAtIndex(4, m22);
        mm.setElementAtIndex(5, 0.0);

        mm.setElementAtIndex(6, m13);
        mm.setElementAtIndex(7, m23);
        mm.setElementAtIndex(8, m33);

        setResult(mm);

        // at this point covariance is expressed in terms of M, and must
        // be expressed in terms of Mg.
        // We know that:
        // Mg = M - I
        // Gg = M * G

        // M = [m11  m12  m13]
        //     [0    m22  m23]
        //     [0    0    m33]

        // G = [g11  g12  g13] = 0
        //     [g21  g22  g23]
        //     [g31  g32  g33]

        // Mg = [sx  mxy  mxz] = [m11 - 1    m12         m13     ]
        //      [myx sy	  myz]   [0          m22 - 1     m23     ]
        //      [mzx mzy  sz ]   [0          0           m33 - 1 ]

        // Gg = [gg11  gg12  gg13] = [m11  m12  m13][g11  g12  g13]
        //      [gg21  gg22  gg23]   [0    m22  m23][g21  g22  g23]
        //      [gg31  gg32  gg33]   [0    0    m33][g31  g32  g33]

        // Defining the linear application:
        // F(M) = F(m11, m12, m22, m32=0, m13, m23, m33)
        // as:
        // [sx] =   [m11 - 1]
        // [sy]     [m22 - 1]
        // [sz]     [m33 - 1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [0]
        // [myz]    [m23]
        // [mzx]    [0]
        // [mzy]    [0]
        // [gg11]   [0]
        // [gg21]   [0]
        // [gg31]   [0]
        // [gg12]   [0]
        // [gg22]   [0]
        // [gg32]   [0]
        // [gg13]   [0]
        // [gg23]   [0]
        // [gg33]   [0]

        // Then the Jacobian of F(M) is:
        // J = [1    0    0    0    0    0]
        //     [0    0    1    0    0    0]
        //     [0    0    0    0    0    1]
        //     [0    1    0    0    0    0]
        //     [0    0    0    1    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    1    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]
        //     [0    0    0    0    0    0]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS_AND_CROSS_BIASES, COMMON_Z_AXIS_UNKNOWNS);

        jacobian.setElementAt(0, 0, 1.0);
        jacobian.setElementAt(1, 2, 1.0);
        jacobian.setElementAt(2, 5, 1.0);

        jacobian.setElementAt(3, 1, 1.0);
        jacobian.setElementAt(4, 3, 1.0);

        jacobian.setElementAt(6, 4, 1.0);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Internal method to perform general calibration when G-dependant cross
     * biases are ignored.
     *
     * @throws AlgebraException                         if accelerometer parameters prevent fixing
     *                                                  measured accelerometer values due to numerical instabilities.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateGeneral() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {

return create(groundTruthGravityNorm, measurements, commonAxisUsed, initialBias, initialMa, listener,
                DEFAULT_ROBUST_METHOD);
    }

    /**
     * Computes error of preliminary result respect a given measurement for current gravity norm.
     *
     * @param measurement       a measurement.
     * @param preliminaryResult a preliminary result.
     * @return computed error.
     */
    protected double computeError(
            final StandardDeviationBodyKinematics measurement, final PreliminaryResult preliminaryResult) {

        try {
            // We know that measured specific force is:
            // fmeas = ba + (I + Ma) * ftrue

            // fmeas - ba = (I + Ma) * ftrue

            // ftrue = (I + Ma)^-1 * (fmeas - ba)

            // We know that ||ftrue|| should be equal to the gravity value at current Earth
            // position
            // ||ftrue|| = g ~ 9.81 m/s^2

            final var estBiases = preliminaryResult.estimatedBiases;
            final var estMa = preliminaryResult.estimatedMa;

            if (identity == null) {
                identity = Matrix.identity(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }

            if (tmp1 == null) {
                tmp1 = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }

            if (tmp2 == null) {
                tmp2 = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }

            if (tmp3 == null) {
                tmp3 = new Matrix(BodyKinematics.COMPONENTS, 1);
            }

            if (tmp4 == null) {
                tmp4 = new Matrix(BodyKinematics.COMPONENTS, 1);
            }

            identity.add(estMa, tmp1);

            Utils.inverse(tmp1, tmp2);

            final var kinematics = measurement.getKinematics();
            final var fmeasX = kinematics.getFx();
            final var fmeasY = kinematics.getFy();
            final var fmeasZ = kinematics.getFz();

            final var bx = estBiases[0];
            final var by = estBiases[1];
            final var bz = estBiases[2];

            tmp3.setElementAtIndex(0, fmeasX - bx);
            tmp3.setElementAtIndex(1, fmeasY - by);
            tmp3.setElementAtIndex(2, fmeasZ - bz);

            tmp2.multiply(tmp3, tmp4);

            final var norm = Utils.normF(tmp4);
            final var diff = groundTruthGravityNorm - norm;

final var jacobian = new Matrix(GENERAL_UNKNOWNS_AND_CROSS_BIASES, GENERAL_UNKNOWNS_AND_CROSS_BIASES);

        jacobian.setElementAt(0, 0, m11);
        jacobian.setElementAt(0, 1, m12);
        jacobian.setElementAt(0, 2, m13);
        jacobian.setElementAt(0, 3, bx);
        jacobian.setElementAt(0, 6, by);
        jacobian.setElementAt(0, 9, bz);

        jacobian.setElementAt(1, 0, m21);
        jacobian.setElementAt(1, 1, m22);
        jacobian.setElementAt(1, 2, m23);
        jacobian.setElementAt(1, 4, bx);
        jacobian.setElementAt(1, 7, by);
        jacobian.setElementAt(1, 10, bz);

        jacobian.setElementAt(2, 0, m31);
        jacobian.setElementAt(2, 1, m32);
        jacobian.setElementAt(2, 2, m33);
        jacobian.setElementAt(2, 5, bx);
        jacobian.setElementAt(2, 8, by);
        jacobian.setElementAt(2, 11, bz);

        jacobian.setElementAt(3, 3, 1.0);
        jacobian.setElementAt(4, 7, 1.0);
        jacobian.setElementAt(5, 11, 1.0);

        jacobian.setElementAt(6, 6, 1.0);
        jacobian.setElementAt(7, 9, 1.0);
        jacobian.setElementAt(8, 4, 1.0);

        jacobian.setElementAt(9, 10, 1.0);
        jacobian.setElementAt(10, 5, 1.0);
        jacobian.setElementAt(11, 8, 1.9);

}

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated gyroscope x-axis scale factor.
     *
     * @return estimated gyroscope x-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-axis scale factor.
     *
     * @return estimated gyroscope y-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated gyroscope z-axis scale factor.
     *
     * @return estimated gyroscope z-axis scale factor or null
     * if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated gyroscope x-y cross-coupling error.
     *
     * @return estimated gyroscope x-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated gyroscope x-z cross-coupling error.
     *
     * @return estimated gyroscope x-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated gyroscope y-x cross-coupling error.
     *
     * @return estimated gyroscope y-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated gyroscope y-z cross-coupling error.
     *
     * @return estimated gyroscope y-z cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated gyroscope z-x cross-coupling error.
     *
     * @return estimated gyroscope z-x cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated gyroscope z-y cross-coupling error.
     *
     * @return estimated gyroscope z-y cross-coupling error or null
     * if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     * This instance allows any 3x3 matrix.
     *
     * @return estimated G-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bgx, bgy, bgz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32,
     * gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets variance of estimated x coordinate of gyroscope bias expressed in (rad^2/s^2).
     *
     * @return variance of estimated x coordinate of gyroscope bias or null if not available.
     */
    public Double getEstimatedBiasXVariance() {

estimatedMa.setElementAt(i, i, estimatedMa.getElementAt(i, i) - 1.0);
        }

        // since only a constant term is subtracted, covariance is preserved
        estimatedCovariance = fitter.getCovar();
        estimatedChiSq = fitter.getChisq();
        estimatedMse = fitter.getMse();
    }

    /**
     * Computes estimated true specific force squared norm using current measured
     * specific force and provided parameters for the general case.
     * This method is internally executed during gradient estimation and
     * Levenberg-Marquardt fitting needed for calibration computation.
     *
     * @param params array containing current parameters for the general purpose case.
     *               Must have length 9.
     * @return estimated true specific force squared norm.
     * @throws EvaluationException if there are numerical instabilities.
     */
    private double evaluateGeneral(final double[] params) throws EvaluationException {
        final var m11 = params[0];
        final var m21 = params[1];
        final var m31 = params[2];

        final var m12 = params[3];
        final var m22 = params[4];
        final var m32 = params[5];

        final var m13 = params[6];
        final var m23 = params[7];
        final var m33 = params[8];

        return evaluate(m11, m21, m31, m12, m22, m32, m13, m23, m33);
    }

    /**
     * Computes estimated true specific force squared norm using current measured
     * specific force and provided parameters when common z-axis is assumed.
     * This method is internally executed during gradient estimation and
     * Levenberg-Marquardt fitting needed for calibration computation.
     *
     * @param params array containing current parameters for the common z-axis case.
     *               Must have length 6.
     * @return estimated true specific force squared norm.
     * @throws EvaluationException if there are numerical instabilities.
     */
    private double evaluateCommonAxis(final double[] params) throws EvaluationException {
        final var m11 = params[0];

        final var m12 = params[1];
        final var m22 = params[2];

        final var m13 = params[3];
        final var m23 = params[4];
        final var m33 = params[5];

        return evaluate(m11, 0.0, 0.0, m12, m22, 0.0, m13, m23, m33);
    }

    /**
     * Computes estimated true specific force squared norm using current measured
     * specific force and provided parameters.
     * This method is internally executed during gradient estimation and
     * Levenberg-Marquardt fitting needed for calibration computation.
     *
     * @param m11 element 1,1 of cross-coupling error matrix.
     * @param m21 element 2,1 of cross-coupling error matrix.
     * @param m31 element 3,1 of cross-coupling error matrix.
     * @param m12 element 1,2 of cross-coupling error matrix.
     * @param m22 element 2,2 of cross-coupling error matrix.
     * @param m32 element 3,2 of cross-coupling error matrix.
     * @param m13 element 1,3 of cross-coupling error matrix.
     * @param m23 element 2,3 of cross-coupling error matrix.
     * @param m33 element 3,3 of cross-coupling error matrix.
     * @return estimated true specific force squared norm.
     * @throws EvaluationException if there are numerical instabilities.
     */
    private double evaluate(final double m11, final double m21, final double m31,
                            final double m12, final double m22, final double m32,
                            final double m13, final double m23, final double m33) throws EvaluationException {

        // fmeas = M*(ftrue + b)

        // ftrue = M^-1*fmeas - b

        try {
            if (fmeas == null) {

final boolean commonAxisUsed, final RobustKnownFrameAccelerometerCalibratorListener listener) {
        super(measurements, commonAxisUsed, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether calibrator is ready to find a solution.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing bias, scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<PreliminaryResult>() {

private double evaluate(final double m11, final double m21, final double m31,
                            final double m12, final double m22, final double m32,
                            final double m13, final double m23, final double m33) throws EvaluationException {

        // Ωmeas = M*(Ωtrue + b)
        // Ωtrue = M^-1 * Ωmeas - b

        try {
            if (measAngularRate == null) {
                measAngularRate = new Matrix(BodyKinematics.COMPONENTS, 1);
            }
            if (m == null) {
                m = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }
            if (invM == null) {
                invM = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }
            if (b == null) {
                b = new Matrix(BodyKinematics.COMPONENTS, 1);
            }
            if (trueAngularRate == null) {
                trueAngularRate = new Matrix(BodyKinematics.COMPONENTS, 1);
            }

            measAngularRate.setElementAtIndex(0, measAngularRateX);
            measAngularRate.setElementAtIndex(1, measAngularRateY);
            measAngularRate.setElementAtIndex(2, measAngularRateZ);

            m.setElementAt(0, 0, m11);
            m.setElementAt(1, 0, m21);
            m.setElementAt(2, 0, m31);

            m.setElementAt(0, 1, m12);
            m.setElementAt(1, 1, m22);
            m.setElementAt(2, 1, m32);

            m.setElementAt(0, 2, m13);
            m.setElementAt(1, 2, m23);
            m.setElementAt(2, 2, m33);

            Utils.inverse(m, invM);

            b.setElementAtIndex(0, biasX);

this(measurements, bias, commonAxisUsed, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<Matrix>() {

public int getMinimumRequiredMeasurements() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start the calibration.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Estimates accelerometer calibration parameters containing bias, scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if calibration fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }

        if (!isReady()) {
            throw new NotReadyException();
        }

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            if (commonAxisUsed) {
                calibrateCommonAxis();
            } else {
                calibrateGeneral();
            }

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final AlgebraException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return array containing x,y,z components of estimated accelerometer biases.
     */
    @Override
    public double[] getEstimatedBiases() {
        return estimatedBiases;
    }

    /**
     * Gets array containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where estimated accelerometer biases will be stored.
     * @return true if result instance was updated, false otherwise (when estimation
     * is not yet available).
     */
    @Override
    public boolean getEstimatedBiases(final double[] result) {
        if (estimatedBiases != null) {
            System.arraycopy(estimatedBiases, 0, result, 0, estimatedBiases.length);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @return column matrix containing x,y,z components of estimated accelerometer
     * biases.
     */
    @Override
    public Matrix getEstimatedBiasesAsMatrix() {
        return estimatedBiases != null ? Matrix.newFromArray(estimatedBiases) : null;
    }

    /**
     * Gets column matrix containing x,y,z components of estimated accelerometer biases
     * expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be stored.
     * @return true if result was updated, false otherwise.
     * @throws WrongSizeException if provided result instance has invalid size.
     */
    @Override
    public boolean getEstimatedBiasesAsMatrix(final Matrix result) throws WrongSizeException {
        if (estimatedBiases != null) {
            result.fromArray(estimatedBiases);
            return true;
        } else {
            return false;
        }
    }

    /**
     * Gets x coordinate of estimated accelerometer bias expressed in meters per
     * squared second (m/s^2).
     *
     * @return x coordinate of estimated accelerometer bias or null if not available.
     */
    @Override
    public Double getEstimatedBiasFx() {

running = false;
        }
    }

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {
        return estimatedMa;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy.
     *
     * @return estimated covariance matrix for estimated calibration parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

this(measurements, bias, commonAxisUsed, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<Matrix>() {

super(measurements, bias, commonAxisUsed, listener);
        internalSetQualityScores(qualityScores);
    }

    /**
     * Gets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not when testing possible solutions.
     * The threshold refers to the amount of error on norm between measured specific forces and the
     * ones generated with estimated calibration parameters provided for each sample.
     *
     * @param threshold threshold to determine whether samples are inliers or not.
     * @throws IllegalArgumentException if provided value is equal or less than zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Returns quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @return quality scores corresponding to each sample.
     */
    @Override
    public double[] getQualityScores() {
        return qualityScores;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * The larger the score value the better the quality of the sample.
     *
     * @param qualityScores quality scores corresponding to each sample.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than minimum required samples.
     * @throws LockedException          if calibrator is currently running.
     */
    @Override
    public void setQualityScores(final double[] qualityScores) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        internalSetQualityScores(qualityScores);
    }

    /**
     * Indicates whether solver is ready to find a solution.
     *
     * @return true if solver is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return super.isReady() && qualityScores != null && qualityScores.length == measurements.size();
    }

    /**
     * Indicates whether inliers must be computed and kept.
     *
     * @return true if inliers must be computed and kept, false if inliers
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepInliersEnabled() {
        return computeAndKeepInliers;
    }

    /**
     * Specifies whether inliers must be computed and kept.
     *
     * @param computeAndKeepInliers true if inliers must be computed and kept,
     *                              false if inliers only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepInliersEnabled(final boolean computeAndKeepInliers) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepInliers = computeAndKeepInliers;
    }

    /**
     * Indicates whether residuals must be computed and kept.
     *
     * @return true if residuals must be computed and kept, false if residuals
     * only need to be computed but not kept.
     */
    public boolean isComputeAndKeepResiduals() {
        return computeAndKeepResiduals;
    }

    /**
     * Specifies whether residuals must be computed and kept.
     *
     * @param computeAndKeepResiduals true if residuals must be computed and kept,
     *                                false if residuals only need to be computed but not kept.
     * @throws LockedException if calibrator is currently running.
     */
    public void setComputeAndKeepResidualsEnabled(final boolean computeAndKeepResiduals) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.computeAndKeepResiduals = computeAndKeepResiduals;
    }

    /**
     * Estimates gyroscope calibration parameters containing bias, scale factors
     * cross-coupling errors and g-dependant cross biases.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new PROSACRobustEstimator<>(new PROSACRobustEstimatorListener<PreliminaryResult>() {

running = false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy.
     *
     * @return estimated covariance matrix for estimated position.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

}

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated chi square value.
     *
     * @return estimated chi square value.
     */
    @Override
    public double getEstimatedChiSq() {
        return estimatedChiSq;
    }

    /**
     * Gets estimated mean square error respect to provided measurements.
     *
     * @return estimated mean square error respect to provided measurements.
     */
    @Override
    public double getEstimatedMse() {
        return estimatedMse;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): bx, by, bz, sx, sy, sz,
     * mxy, mxz, myx, myz, mzx, mzy.
     *
     * @return estimated covariance matrix for estimated calibration parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

    /**
     * Gets variance of estimated x coordinate of magnetometer bias expressed in
     * squared Teslas (T^2).
     *
     * @return variance of estimated x coordinate of magnetometer bias or null if
     * not available.
     */
    public Double getEstimatedHardIronXVariance() {

initialMm, listener, DEFAULT_ROBUST_METHOD);
    }

    /**
     * Computes error of a preliminary result respect a given measurement.
     *
     * @param measurement       a measurement.
     * @param preliminaryResult a preliminary result.
     * @return computed error.
     */
    protected double computeError(
            final StandardDeviationBodyMagneticFluxDensity measurement, final PreliminaryResult preliminaryResult) {

        try {
            // The magnetometer model is:
            // mBmeas = bm + (I + Mm) * mBtrue

            // mBmeas - bm = (I + Mm) * mBtrue

            // mBtrue = (I + Mm)^-1 * (mBmeas - ba)

            // We know that ||mBtrue||should be equal to the magnitude of the
            // Earth magnetic field at provided location

            final var estimatedBiases = preliminaryResult.estimatedHardIron;
            final var estMm = preliminaryResult.estimatedMm;

            if (identity == null) {
                identity = Matrix.identity(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            }

            if (tmp1 == null) {
                tmp1 = new Matrix(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
            }

            if (tmp2 == null) {
                tmp2 = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }

            if (tmp3 == null) {
                tmp3 = new Matrix(BodyKinematics.COMPONENTS, 1);
            }

            if (tmp4 == null) {
                tmp4 = new Matrix(BodyKinematics.COMPONENTS, 1);
            }

            identity.add(estMm, tmp1);

            Utils.inverse(tmp1, tmp2);

            final var measuredMagneticFluxDensity = measurement.getMagneticFluxDensity();
            final var bMeasX = measuredMagneticFluxDensity.getBx();
            final var bMeasY = measuredMagneticFluxDensity.getBy();
            final var bMeasZ = measuredMagneticFluxDensity.getBz();

            final var bx = estimatedBiases[0];
            final var by = estimatedBiases[1];
            final var bz = estimatedBiases[2];

            tmp3.setElementAtIndex(0, bMeasX - bx);
            tmp3.setElementAtIndex(1, bMeasY - by);
            tmp3.setElementAtIndex(2, bMeasZ - bz);

            tmp2.multiply(tmp3, tmp4);

            final var norm = Utils.normF(tmp4);
            final var diff = groundTruthMagneticFluxDensityNorm - norm;

state = new INSLooselyCoupledKalmanState();
        }
    }

    /**
     * Corrects provided kinematics by taking into account currently estimated
     * specific force and angular rate biases.
     * This method stores the result into the variable member containing corrected
     * kinematics values.
     *
     * @param kinematics kinematics instance to be corrected.
     */
    private void correctKinematics(final BodyKinematics kinematics) {
        if (correctedKinematics == null) {
            correctedKinematics = new BodyKinematics();
        }

        final double accelBiasX;
        final double accelBiasY;
        final double accelBiasZ;
        final double gyroBiasX;
        final double gyroBiasY;
        final double gyroBiasZ;
        if (state != null) {
            accelBiasX = getValueOrZero(state.getAccelerationBiasX());
            accelBiasY = getValueOrZero(state.getAccelerationBiasY());
            accelBiasZ = getValueOrZero(state.getAccelerationBiasZ());
            gyroBiasX = getValueOrZero(state.getGyroBiasX());
            gyroBiasY = getValueOrZero(state.getGyroBiasY());
            gyroBiasZ = getValueOrZero(state.getGyroBiasZ());
        } else {
            accelBiasX = 0.0;
            accelBiasY = 0.0;
            accelBiasZ = 0.0;
            gyroBiasX = 0.0;
            gyroBiasY = 0.0;
            gyroBiasZ = 0.0;
        }

        final var fx = kinematics.getFx();
        final var fy = kinematics.getFy();
        final var fz = kinematics.getFz();
        final var angularRateX = kinematics.getAngularRateX();
        final var angularRateY = kinematics.getAngularRateY();
        final var angularRateZ = kinematics.getAngularRateZ();

        correctedKinematics.setSpecificForceCoordinates(fx - accelBiasX, fy - accelBiasY, fz - accelBiasZ);
        correctedKinematics.setAngularRateCoordinates(
                angularRateX - gyroBiasX,
                angularRateY - gyroBiasY,
                angularRateZ - gyroBiasZ);
    }

    /**
     * Returns provided value if not infinity and not NaN.
     *
     * @param value value to be returned.
     * @return value or 0.0.
     */
    private double getValueOrZero(final double value) {
        if (Double.isNaN(value) || Double.isInfinite(value)) {
            return 0.0;
        } else {
            return value;
        }
    }
}

final var a = new Matrix(rows, COMMON_Z_AXIS_UNKNOWNS);
        final var b = new Matrix(rows, 1);
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredMagneticFluxDensity = measurement.getMagneticFluxDensity();

            // estimate Earth magnetic flux density at frame position and
            // timestamp using WMM
            final var ecefFrame = measurement.getFrame();
            ECEFtoNEDFrameConverter.convertECEFtoNED(ecefFrame, nedFrame);

            final var year = measurement.getYear();

            final var latitude = nedFrame.getLatitude();
            final var longitude = nedFrame.getLongitude();
            final var height = nedFrame.getHeight();

            nedFrame.getCoordinateTransformation(cbn);
            cbn.inverse(cnb);

            wmmEstimator.estimate(latitude, longitude, height, year, earthB);

            // estimate expected body magnetic flux density taking into
            // account body attitude (inverse of frame orientation) and
            // estimated Earth magnetic flux density
            BodyMagneticFluxDensityEstimator.estimate(earthB, cnb, expectedMagneticFluxDensity);

            final var bMeasX = measuredMagneticFluxDensity.getBx();
            final var bMeasY = measuredMagneticFluxDensity.getBy();
            final var bMeasZ = measuredMagneticFluxDensity.getBz();

            final var bTrueX = expectedMagneticFluxDensity.getBx();
            final var bTrueY = expectedMagneticFluxDensity.getBy();
            final var bTrueZ = expectedMagneticFluxDensity.getBz();

            a.setElementAt(i, 0, 1.0);
            a.setElementAt(i, 3, bTrueX);
            a.setElementAt(i, 6, bTrueY);
            a.setElementAt(i, 7, bTrueZ);

            b.setElementAtIndex(i, bMeasX - bTrueX);
            i++;

            a.setElementAt(i, 1, 1.0);
            a.setElementAt(i, 4, bTrueY);
            a.setElementAt(i, 8, bTrueZ);

} catch (final AlgebraException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing g-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

biasZ = convertAcceleration(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param bias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        if (bias.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        biasX = bias[0];
        biasY = bias[1];
        biasZ = bias[2];
    }

    /**
     * Gets known accelerometer bias as a column matrix.
     *
     * @return known accelerometer bias as a column matrix.
     */
    @Override
    public Matrix getBiasAsMatrix() {
        Matrix result;
        try {
            result = new Matrix(BodyKinematics.COMPONENTS, 1);
            getBiasAsMatrix(result);
        } catch (final WrongSizeException ignore) {
            // never happens
            result = null;
        }
        return result;
    }

    /**
     * Gets known accelerometer bias as a column matrix.
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void getBiasAsMatrix(final Matrix result) {
        if (result.getRows() != BodyKinematics.COMPONENTS || result.getColumns() != 1) {
            throw new IllegalArgumentException();
        }
        result.setElementAtIndex(0, biasX);
        result.setElementAtIndex(1, biasY);
        result.setElementAtIndex(2, biasZ);
    }

    /**
     * Sets known accelerometer bias as a column matrix.
     *
     * @param bias accelerometer bias to be set.
     * @throws LockedException          if calibrator is currently running
     * @throws IllegalArgumentException if provided matrix is not 3x1.
     */
    @Override
    public void setBias(final Matrix bias) throws LockedException {

estimatedMg = preliminaryResult.estimatedMg;
            estimatedGg = preliminaryResult.estimatedGg;
            estimatedMse = preliminaryResult.estimatedMse;
            estimatedChiSq = preliminaryResult.estimatedChiSq;
        }
    }

    /**
     * Converts acceleration instance to meters per squared second.
     *
     * @param acceleration acceleration instance to be converted.
     * @return converted value.
     */
    private static double convertAcceleration(final Acceleration acceleration) {
        return AccelerationConverter.convert(acceleration.getValue().doubleValue(), acceleration.getUnit(),
                AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Converts angular speed value and unit to radians per second.
     *
     * @param value angular speed value.
     * @param unit  unit of angular speed value.
     * @return converted value.
     */
    private static double convertAngularSpeed(final double value, final AngularSpeedUnit unit) {
        return AngularSpeedConverter.convert(value, unit, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Converts angular speed instance to radians per second.
     *
     * @param angularSpeed angular speed instance to be converted.
     * @return converted value.
     */
    private static double convertAngularSpeed(final AngularSpeed angularSpeed) {
        return convertAngularSpeed(angularSpeed.getValue().doubleValue(), angularSpeed.getUnit());
    }

    /**
     * Fixes a measured kinematics instance using current
     *
     * @param measuredKinematics a measured kinematics instance.
     * @param result             instance where fixed values will be stored.
     * @throws AlgebraException if accelerometer or gyroscope parameters
     *                          contain numerical instabilities.
     */
    private void fixKinematics(final BodyKinematics measuredKinematics, final BodyKinematics result)
            throws AlgebraException {

        measuredSpecificForce[0] = measuredKinematics.getFx();
        measuredSpecificForce[1] = measuredKinematics.getFy();
        measuredSpecificForce[2] = measuredKinematics.getFz();
        accelerationFixer.fix(measuredSpecificForce, fixedSpecificForce);

        measuredAngularRate[0] = measuredKinematics.getAngularRateX();
        measuredAngularRate[1] = measuredKinematics.getAngularRateY();
        measuredAngularRate[2] = measuredKinematics.getAngularRateZ();
        angularRateFixer.fix(measuredAngularRate, fixedSpecificForce, fixedAngularRate);

        result.setSpecificForceCoordinates(fixedSpecificForce[0], fixedSpecificForce[1], fixedSpecificForce[2]);
        result.setAngularRateCoordinates(fixedAngularRate[0], fixedAngularRate[1], fixedAngularRate[2]);
    }

    /**
     * Internal class containing estimated preliminary result.
     */
    protected static class PreliminaryResult {
        /**
         * Estimated gyroscope biases for each IMU axis expressed in radians per second
         * (rad/s).
         */
        private double[] estimatedBiases;

running = false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing g-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

    /**
     * Gets estimated covariance matrix for estimated position.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy, gg11, gg21, gg31, gg12, gg22, gg32, gg13, gg23, gg33.
     *
     * @return estimated covariance matrix for estimated position.
     */
    @Override
    public Matrix getEstimatedCovariance() {
        return estimatedCovariance;
    }

public void setListener(final EasyGyroscopeCalibratorListener listener) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required sequences.
     *
     * @return minimum number of required sequences.
     */
    @Override
    public int getMinimumRequiredMeasurementsOrSequences() {
        if (commonAxisUsed) {
            if (estimateGDependentCrossBiases) {
                return MINIMUM_SEQUENCES_COMMON_Z_AXIS_AND_CROSS_BIASES;
            } else {
                return MINIMUM_SEQUENCES_COMMON_Z_AXIS;
            }
        } else {
            if (estimateGDependentCrossBiases) {
                return MINIMUM_SEQUENCES_GENERAL_AND_CROSS_BIASES;
            } else {
                return MINIMUM_SEQUENCES_GENERAL;
            }
        }
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return sequences != null && sequences.size() >= getMinimumRequiredMeasurementsOrSequences();
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Estimates gyroscope calibration parameters containing bias, scale factors,
     * cross-coupling errors and G-dependent coupling.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }

        if (!isReady()) {
            throw new NotReadyException();
        }

        try {
            running = true;

            reset();

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            if (commonAxisUsed) {
                if (estimateGDependentCrossBiases) {
                    calibrateCommonAxisAndGDependentCrossBiases();
                } else {
                    calibrateCommonAxis();
                }
            } else {
                if (estimateGDependentCrossBiases) {
                    calibrateGeneralAndGDependentCrossBiases();
                } else {
                    calibrateGeneral();
                }
            }

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final FittingException | AlgebraException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated gyroscope biases
     * expressed in radians per second (rad/s).
     *
     * @return array containing x,y,z components of estimated gyroscope biases.
     */
    @Override
    public double[] getEstimatedBiases() {

final KnownBiasTurntableGyroscopeCalibratorListener listener) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurementsOrSequences() {
        if (commonAxisUsed) {
            if (estimateGDependentCrossBiases) {
                return MINIMUM_MEASUREMENTS_COMMON_Z_AXIS_AND_CROSS_BIASES;
            } else {
                return MINIMUM_MEASUREMENTS_COMMON_Z_AXIS;
            }
        } else {
            if (estimateGDependentCrossBiases) {
                return MINIMUM_MEASUREMENTS_GENERAL_AND_CROSS_BIASES;
            } else {
                return MINIMUM_MEASUREMENTS_GENERAL;
            }
        }
    }

    /**
     * Indicates whether calibrator is ready to start.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= getMinimumRequiredMeasurementsOrSequences();
    }

    /**
     * Indicates whether calibrator is currently running or not.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Estimates gyroscope calibration parameters containing bias, scale factors,
     * cross-coupling errors and G-dependent coupling.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }

        if (!isReady()) {
            throw new NotReadyException();
        }

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            if (commonAxisUsed) {
                if (estimateGDependentCrossBiases) {
                    calibrateCommonAxisAndGDependentCrossBiases();
                } else {
                    calibrateCommonAxis();
                }
            } else {
                if (estimateGDependentCrossBiases) {
                    calibrateGeneralAndGDependentCrossBiases();
                } else {
                    calibrateGeneral();
                }
            }

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException
                       | InvalidSourceAndDestinationFrameTypeException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMg() {

} catch (final AlgebraException | IOException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

} catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

return create(groundTruthGravityNorm, measurements, commonAxisUsed, bias, initialMa, listener,
                DEFAULT_ROBUST_METHOD);
    }

    /**
     * Computes error of preliminary result respect a given measurement for current gravity norm.
     *
     * @param measurement       a measurement.
     * @param preliminaryResult a preliminary result.
     * @return computed error.
     */
    protected double computeError(
            final StandardDeviationBodyKinematics measurement, final PreliminaryResult preliminaryResult) {

        try {
            // We know that measured specific force is:
            // fmeas = ba + (I + Ma) * ftrue

            // fmeas - ba = (I + Ma) * ftrue

            // ftrue = (I + Ma)^-1 * (fmeas - ba)

            // We know that ||ftrue|| should be equal to the gravity value at current Earth
            // position
            // ||ftrue|| = g ~ 9.81 m/s^2

            final var estMa = preliminaryResult.estimatedMa;

            if (identity == null) {
                identity = Matrix.identity(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }

            if (tmp1 == null) {
                tmp1 = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }

            if (tmp2 == null) {
                tmp2 = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }

            if (tmp3 == null) {
                tmp3 = new Matrix(BodyKinematics.COMPONENTS, 1);
            }

            if (tmp4 == null) {
                tmp4 = new Matrix(BodyKinematics.COMPONENTS, 1);
            }

            identity.add(estMa, tmp1);

            Utils.inverse(tmp1, tmp2);

            final var kinematics = measurement.getKinematics();
            final var fmeasX = kinematics.getFx();
            final var fmeasY = kinematics.getFy();
            final var fmeasZ = kinematics.getFz();

            tmp3.setElementAtIndex(0, fmeasX - biasX);
            tmp3.setElementAtIndex(1, fmeasY - biasY);
            tmp3.setElementAtIndex(2, fmeasZ - biasZ);

            tmp2.multiply(tmp3, tmp4);

            final var norm = Utils.normF(tmp4);
            final var diff = groundTruthGravityNorm - norm;

final var g33 = unknowns.getElementAtIndex(14);

        fillMg(sx, sy, sz, mxy, mxz, 0.0, myz, 0.0, 0.0);
        fillGg(g11, g12, g13, g21, g22, g23, g31, g32, g33);
    }

    /**
     * Internal method to perform general calibration.
     *
     * @throws AlgebraException if there are numerical errors.
     */
    private void calibrateGeneral() throws AlgebraException {
        // The gyroscope model is:
        // Ωmeas = bg + (I + Mg) * Ωtrue + Gg * ftrue + w

        // Ideally a least squares solution tries to minimize noise component, so:
        // Ωmeas = bg + (I + Mg) * Ωtrue + Gg * ftrue

        // Hence:
        // [Ωmeasx] = [bx] + ( [1   0   0] + [sx    mxy    mxz]) [Ωtruex] + [g11   g12   g13][ftruex]
        // [Ωmeasy]   [by]     [0   1   0]   [myx   sy     myz]  [Ωtruey]   [g21   g22   g23][ftruey]
        // [Ωmeasz]   [bz]     [0   0   1]   [mzx   mzy    sz ]  [Ωtruez]   [g31   g32   g33][ftruez]

        // [Ωmeasx] = [bx] + ( [1+sx  mxy    mxz ]) [Ωtruex] + [g11   g12   g13][ftruex]
        // [Ωmeasy]   [by]     [myx   1+sy   myz ]  [Ωtruey]   [g21   g22   g23][ftruey]
        // [Ωmeasz]   [bz]     [mzx   mzy    1+sz]  [Ωtruez]   [g31   g32   g33][ftruez]

        // Ωmeasx = bx + (1+sx) * Ωtruex + mxy * Ωtruey + mxz * Ωtruez + g11 * ftruex + g12 * ftruey + g13 * ftruez
        // Ωmeasy = by + myx * Ωtruex + (1+sy) * Ωtruey + myz * Ωtruez + g21 * ftruex * g22 * ftruey + g23 * ftruez
        // Ωmeasz = bz + mzx * Ωtruex + mzy * Ωtruey + (1+sz) * Ωtruez + g31 * ftruex + g32 * ftruey + g33 * ftruez

        // Where the unknowns are: sx, sy, sz, mxy mxz, myx, myz, mzx, mzy, g11, g12, g13, g21, g22, g23,
        // g31, g32, g33
        // Reordering:
        // Ωmeasx = bx + Ωtruex + sx * Ωtruex + mxy * Ωtruey + mxz * Ωtruez + g11 * ftruex + g12 * ftruey + g13 * ftruez
        // Ωmeasy = by + myx * Ωtruex + Ωtruey + sy * Ωtruey + myz * Ωtruez + g21 * ftruex * g22 * ftruey + g23 * ftruez
        // Ωmeasz = bz + mzx * Ωtruex + mzy * Ωtruey + Ωtruez + sz * Ωtruez + g31 * ftruex + g32 * ftruey + g33 * ftruez

        // Ωmeasx - Ωtruex - bx = sx * Ωtruex + mxy * Ωtruey + mxz * Ωtruez + g11 * ftruex + g12 * ftruey + g13 * ftruez
        // Ωmeasy - Ωtruey - by = myx * Ωtruex + sy * Ωtruey + myz * Ωtruez + g21 * ftruex * g22 * ftruey + g23 * ftruez
        // Ωmeasz - Ωtruez - bz = mzx * Ωtruex + mzy * Ωtruey + sz * Ωtruez + g31 * ftruex + g32 * ftruey + g33 * ftruez

        // [Ωtruex  0       0       Ωtruey  Ωtruez  0       0       0       0       ftruex  ftruey  ftruez  0       0       0       0       0       0     ][sx ] =  [Ωmeasx - Ωtruex - bx]
        // [0       Ωtruey  0       0       0       Ωtruex  Ωtruez  0       0       0       0       0       ftruex  ftruey  ftruez  0       0       0     ][sy ]    [Ωmeasy - Ωtruey - by]
        // [0       0       Ωtruez  0       0       0       0       Ωtruex  Ωtruey  0       0       0       0       0       0       ftruex  ftruey  ftruez][sz ]    [Ωmeasz - Ωtruez - bz]
        //                                                                                                                                                 [mxy]
        //                                                                                                                                                 [mxz]
        //                                                                                                                                                 [myx]
        //                                                                                                                                                 [myz]
        //                                                                                                                                                 [mzx]
        //                                                                                                                                                 [mzy]
        //                                                                                                                                                 [g11]
        //                                                                                                                                                 [g12]
        //                                                                                                                                                 [g13]
        //                                                                                                                                                 [g21]
        //                                                                                                                                                 [g22]
        //                                                                                                                                                 [g23]
        //                                                                                                                                                 [g31]
        //                                                                                                                                                 [g32]
        //                                                                                                                                                 [g33]

        final var expectedKinematics = new BodyKinematics();

        final var rows = EQUATIONS_PER_MEASUREMENT * measurements.size();
        final var a = new Matrix(rows, GENERAL_UNKNOWNS);
        final var b = new Matrix(rows, 1);
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredKinematics = measurement.getKinematics();
            final var ecefFrame = measurement.getFrame();
            final var previousEcefFrame = measurement.getPreviousFrame();
            final var timeInterval = measurement.getTimeInterval();

            ECEFKinematicsEstimator.estimateKinematics(timeInterval, ecefFrame, previousEcefFrame, expectedKinematics);

            final var omegaMeasX = measuredKinematics.getAngularRateX();
            final var omegaMeasY = measuredKinematics.getAngularRateY();
            final var omegaMeasZ = measuredKinematics.getAngularRateZ();

            final var omegaTrueX = expectedKinematics.getAngularRateX();
            final var omegaTrueY = expectedKinematics.getAngularRateY();
            final var omegaTrueZ = expectedKinematics.getAngularRateZ();

            final var fTrueX = expectedKinematics.getFx();
            final var fTrueY = expectedKinematics.getFy();
            final var fTrueZ = expectedKinematics.getFz();

            a.setElementAt(i, 0, omegaTrueX);

running = false;
        }
    }

    /**
     * Gets estimated gyroscope scale factors and cross coupling errors.
     * This is the product of matrix Tg containing cross coupling errors and Kg
     * containing scaling factors.
     * So that:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Kg = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tg = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the gyroscope z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
     * becomes upper diagonal:
     * <pre>
     *     Mg = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated gyroscope scale factors and cross coupling errors.
     */
    @Override
    public Matrix getEstimatedMg() {
        return estimatedMg;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMg != null ? estimatedMg.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMg != null ? estimatedMg.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMg != null ? estimatedMg.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated G-dependent cross biases introduced on the gyroscope by the
     * specific forces sensed by the accelerometer.
     *
     * @return a 3x3 matrix containing g-dependent cross biases.
     */
    @Override
    public Matrix getEstimatedGg() {
        return estimatedGg;
    }

private double evaluate(final double m11, final double m21, final double m31,
                            final double m12, final double m22, final double m32,
                            final double m13, final double m23, final double m33,
                            final double g11, final double g21, final double g31,
                            final double g12, final double g22, final double g32,
                            final double g13, final double g23, final double g33) throws EvaluationException {

        // Ωmeas = bg + (I + Mg) * Ωtrue + Gg * ftrue
        // Ωmeas = M*(Ωtrue + b + G * ftrue)

        // M = I + Mg
        // bg = M*b --> b = M^-1*bg
        // Gg = M*G --> G = M^-1*Gg

        // Ωtrue = M^-1 * Ωmeas - b - G*ftrue

        try {
            if (measAngularRate == null) {
                measAngularRate = new Matrix(BodyKinematics.COMPONENTS, 1);
            }
            if (fmeas == null) {
                fmeas = new Matrix(BodyKinematics.COMPONENTS, 1);
            }
            if (m == null) {
                m = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }
            if (invM == null) {
                invM = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }
            if (b == null) {
                b = new Matrix(BodyKinematics.COMPONENTS, 1);
            }
            if (g == null) {
                g = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }
            if (trueAngularRate == null) {
                trueAngularRate = new Matrix(BodyKinematics.COMPONENTS, 1);
            }
            if (ftrue == null) {
                ftrue = new Matrix(BodyKinematics.COMPONENTS, 1);
            }
            if (tmp == null) {

final var a = new Matrix(rows, COMMON_Z_AXIS_UNKNOWNS);
        final var b = new Matrix(rows, 1);
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredMagneticFluxDensity = measurement.getMagneticFluxDensity();

            // estimate Earth magnetic flux density at frame position and
            // timestamp using WMM
            final var ecefFrame = measurement.getFrame();
            ECEFtoNEDFrameConverter.convertECEFtoNED(ecefFrame, nedFrame);

            final var year = measurement.getYear();

            final var latitude = nedFrame.getLatitude();
            final var longitude = nedFrame.getLongitude();
            final var height = nedFrame.getHeight();

            nedFrame.getCoordinateTransformation(cbn);
            cbn.inverse(cnb);

            wmmEstimator.estimate(latitude, longitude, height, year, earthB);

            // estimate expected body magnetic flux density taking into
            // account body attitude (inverse of frame orientation) and
            // estimated Earth magnetic flux density
            BodyMagneticFluxDensityEstimator.estimate(earthB, cnb, expectedMagneticFluxDensity);

            final var bMeasX = measuredMagneticFluxDensity.getBx();
            final var bMeasY = measuredMagneticFluxDensity.getBy();
            final var bMeasZ = measuredMagneticFluxDensity.getBz();

            final var bTrueX = expectedMagneticFluxDensity.getBx();
            final var bTrueY = expectedMagneticFluxDensity.getBy();
            final var bTrueZ = expectedMagneticFluxDensity.getBz();

            a.setElementAt(i, 0, bTrueX);
            a.setElementAt(i, 1, 0.0);
            a.setElementAt(i, 2, 0.0);
            a.setElementAt(i, 3, bTrueY);
            a.setElementAt(i, 4, bTrueZ);
            a.setElementAt(i, 5, 0.0);

setResult(crossCoupling, bias);

        // at this point covariance is expressed in terms of b and M, and must
        // be expressed in terms of ba and Ma.
        // We know that:

        // b = [bx]
        //     [by]
        //     [bz]

        // M = [m11 	m12 	m13]
        //     [0    	m22 	m23]
        //     [0    	0    	m33]

        // m21 = m31 = m32 = 0

        // and that ba and Ma are expressed as:
        // Ma = M - I
        // ba = M * b

        // Ma = [m11 - 1    m12         m13    ] =  [sx     mxy     mxz]
        //      [0          m22 - 1     m23    ]    [0      sy      myz]
        //      [0          0           m33 - 1]    [0      0       sz ]

        // ba = [m11 * bx + m12 * by + m13 * bz] = 	[bax]
        //      [           m22 * by + m23 * bz]	[bay]
        //      [                      m33 * bz]	[baz]

        // Defining the linear application:
        // F(b, M) = F(bx, by, bz, m11, m12, m22, m13, m23, m33)
        // as:
        // [bax] = 	[m11 * bx + m12 * by + m13 * bz]
        // [bay]	[m22 * by + m23 * bz]
        // [baz]	[m33 * bz]
        // [sx]		[m11 - 1]
        // [sy]		[m22 - 1]
        // [sz]		[m33 -1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [0]
        // [myz]    [m23]
        // [mzx]    [0]
        // [mzy]    [0]

        // Then the Jacobian of F(b, M) is:
        // J = 	[m11  m12  m13  bx  by  0   bz  0   0 ]
        //	    [0    m22  m23  0   0   by  0   bz  0 ]
        //	    [0    0    m33  0   0   0   0   0   bz]
        //	    [0    0    0    1   0   0   0   0   0 ]
        //	    [0    0    0    0   0   1   0   0   0 ]
        //	    [0    0    0    0   0   0   0   0   1 ]
        //	    [0    0    0    0   1   0   0   0   0 ]
        //	    [0    0    0    0   0   0   1   0   0 ]
        //	    [0    0    0    0   0   0   0   0   0 ]
        //	    [0    0    0    0   0   0   0   1   0 ]
        //	    [0    0    0    0   0   0   0   0   0 ]
        //	    [0    0    0    0   0   0   0   0   0 ]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS, COMMON_Z_AXIS_UNKNOWNS);

        jacobian.setElementAt(0, 0, m11);

        jacobian.setElementAt(0, 1, m12);
        jacobian.setElementAt(1, 1, m22);

        jacobian.setElementAt(0, 2, m13);
        jacobian.setElementAt(1, 2, m23);
        jacobian.setElementAt(2, 2, m33);

        jacobian.setElementAt(0, 3, bx);
        jacobian.setElementAt(3, 3, 1.0);

        jacobian.setElementAt(0, 4, by);
        jacobian.setElementAt(6, 4, 1.0);

        jacobian.setElementAt(1, 5, by);
        jacobian.setElementAt(4, 5, 1.0);

        jacobian.setElementAt(0, 6, bz);
        jacobian.setElementAt(7, 6, 1.0);

        jacobian.setElementAt(1, 7, bz);
        jacobian.setElementAt(9, 7, 1.0);

        jacobian.setElementAt(2, 8, bz);
        jacobian.setElementAt(5, 8, 1.0);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Makes proper conversion of internal cross-coupling and bias matrices.
     *
     * @param m internal cross-coupling matrix.
     * @param b internal bias matrix.
     * @throws AlgebraException if a numerical instability occurs.
     */
    private void setResult(final Matrix m, final Matrix b) throws AlgebraException {
        // Because:
        // M = I + Ma
        // b = M^-1*ba

        // Then:
        // Ma = M - I
        // ba = M*b

        if (estimatedBiases == null) {

setResult(m, b);

        // at this point covariance is expressed in terms of b, M and G, and must
        // be expressed in terms of bg, Mg and Gg.
        // We know that:
        // bg = M * b
        // Mg = M - I
        // Gg = M * G = 0

        // b = [bx]
        //     [by]
        //     [bz]

        // M = [m11  m12  m13]
        //     [0    m22  m23]
        //     [0    0    m33]

        // G = [g11  g12  g13] = 0
        //     [g21  g22  g23]
        //     [g31  g32  g33]

        // bg = [m11  m12  m13][bx] = [m11 * bx + m12 * by + m13 * bz] = [bgx]
        //      [0    m22  m23][by]   [           m22 * by + m23 * bz]   [bgy]
        //      [0    0    m33][bz]   [                      m33 * bz]   [bgz]

        // Mg = [sx  mxy  mxz] = [m11 - 1    m12         m13     ]
        //      [myx sy	  myz]   [0          m22 - 1     m23     ]
        //      [mzx mzy  sz ]   [0          0           m33 - 1 ]

        // Gg = [gg11  gg12  gg13] = 0
        //      [gg21  gg22  gg23]
        //      [gg31  gg32  gg33]

        // Defining the linear application:
        // F(b, M) = F(bx, by, bz, m11, m12, m22, m13, m23, m33)
        // as:
        // [bgx] =  [m11 * bx + m12 * by + m13 * bz]
        // [bgy]    [           m22 * by + m23 * bz]
        // [bgz]    [                      m33 * bz]
        // [sx]     [m11 - 1]
        // [sy]     [m22 - 1]
        // [sz]     [m33 - 1]
        // [mxy]    [m12]
        // [mxz]    [m13]
        // [myx]    [0]
        // [myz]    [m23]
        // [mzx]    [0]
        // [mzy]    [0]
        // [gg11]   [0]
        // [gg21]   [0]
        // [gg31]   [0]
        // [gg12]   [0]
        // [gg22]   [0]
        // [gg32]   [0]
        // [gg13]   [0]
        // [gg23]   [0]
        // [gg33]   [0]

        // Then the Jacobian of F(b, M) is:
        // J = [m11  m12  m13  bx   by   0    bz   0    0  ]
        //     [0    m22  m23  0    0    by   0    bz   0  ]
        //     [0    0    m33  0    0    0    0    0    bz ]
        //     [0    0    0    1    0    0    0    0    0  ]
        //     [0    0    0    0    0    1    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    1  ]
        //     [0    0    0    0    1    0    0    0    0  ]
        //     [0    0    0    0    0    0    1    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    1    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]
        //     [0    0    0    0    0    0    0    0    0  ]

        // We know that the propagated covariance is J * Cov * J', hence:
        final var jacobian = new Matrix(GENERAL_UNKNOWNS_AND_CROSS_BIASES, COMMON_Z_AXIS_UNKNOWNS);

        jacobian.setElementAt(0, 0, m11);
        jacobian.setElementAt(0, 1, m12);
        jacobian.setElementAt(0, 2, m13);
        jacobian.setElementAt(0, 3, bx);
        jacobian.setElementAt(0, 4, by);
        jacobian.setElementAt(0, 6, bz);

        jacobian.setElementAt(1, 1, m22);
        jacobian.setElementAt(1, 2, m23);
        jacobian.setElementAt(1, 5, by);
        jacobian.setElementAt(1, 7, bz);

        jacobian.setElementAt(2, 2, m33);
        jacobian.setElementAt(2, 8, bz);

        jacobian.setElementAt(3, 3, 1.0);
        jacobian.setElementAt(4, 5, 1.0);
        jacobian.setElementAt(5, 8, 1.0);

        jacobian.setElementAt(6, 4, 1.0);
        jacobian.setElementAt(7, 6, 1.0);

        jacobian.setElementAt(9, 7, 1.0);

        final var jacobianTrans = jacobian.transposeAndReturnNew();
        jacobian.multiply(estimatedCovariance);
        jacobian.multiply(jacobianTrans);
        estimatedCovariance = jacobian;
    }

    /**
     * Internal method to perform general calibration when G-dependant cross
     * biases are ignored.
     *
     * @throws AlgebraException                         if accelerometer parameters prevent fixing
     *                                                  measured accelerometer values due to numerical instabilities.
     * @throws FittingException                         if no convergence to solution is found.
     * @throws com.irurueta.numerical.NotReadyException if fitter is not ready.
     */
    private void calibrateGeneral() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {

}

    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {
        return estimatedMa;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 1) : null;
    }

    /**
     * Gets estimated covariance matrix for estimated calibration parameters.
     * Diagonal elements of the matrix contains variance for the following
     * parameters (following indicated order): sx, sy, sz, mxy, mxz, myx,
     * myz, mzx, mzy.
     * This is only available when result has been refined and covariance
     * is kept.
     *
     * @return estimated covariance matrix for estimated calibration parameters.
     */
    @Override
    public Matrix getEstimatedCovariance() {

final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,
            final double timeInterval, final List<StandardDeviationBodyKinematics> measurements,
            final boolean commonAxisUsed, final boolean estimateGDependentCrossBiases, final double[] bias,
            final Matrix initialMg, final Matrix initialGg, final double[] accelerometerBias,
            final Matrix accelerometerMa, final RobustKnownBiasTurntableGyroscopeCalibratorListener listener,
            final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case LMEDS -> new LMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case MSAC -> new MSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case PROSAC -> new PROSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    qualityScores, position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            default -> new PROMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    qualityScores, position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param qualityScores                 quality scores corresponding to each provided
     *                                      measurement. The larger the score value the better
     *                                      the quality of the sample.
     * @param position                      position where body kinematics
     *                                      measures have been taken.
     * @param turntableRotationRate         constant rotation rate at which
     *                                      the turntable is spinning. Must
     *                                      be expressed in radians per
     *                                      second (rad/s).
     * @param timeInterval                  time interval between measurements
     *                                      being captured expressed in
     *                                      seconds (s).
     * @param measurements                  collection of body kinematics
     *                                      measurements with standard
     *                                      deviations taken at the same
     *                                      position with zero velocity and
     *                                      unknown different orientations.
     * @param commonAxisUsed                indicates whether z-axis is
     *                                      assumed to be common for
     *                                      accelerometer and gyroscope.
     * @param estimateGDependentCrossBiases true if G-dependent cross biases
     *                                      will be estimated, false
     *                                      otherwise.
     * @param bias                          known gyroscope bias. This
     *                                      must be 3x1 and is expressed in
     *                                      radians per second (rad/s).
     * @param initialMg                     initial gyroscope scale factors
     *                                      and cross coupling errors matrix.
     *                                      Must be 3x3.
     * @param initialGg                     initial gyroscope G-dependent
     *                                      cross biases introduced on the
     *                                      gyroscope by the specific forces
     *                                      sensed by the accelerometer. Must
     *                                      be 3x3.
     * @param accelerometerBias             known accelerometer bias. This
     *                                      must have length 3 and is
     *                                      expressed in meters per squared
     *                                      second (m/s^2).
     * @param accelerometerMa               known accelerometer scale factors
     *                                      and cross coupling matrix. Must
     *                                      be 3x3.
     * @param method                        robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size, if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative or
     *                                  if provided quality scores length is
     *                                  smaller than 7 samples.
     */
    public static RobustKnownBiasTurntableGyroscopeCalibrator create(
            final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,

final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,
            final double timeInterval, final List<StandardDeviationBodyKinematics> measurements,
            final boolean commonAxisUsed, final boolean estimateGDependentCrossBiases, final double[] initialBias,
            final Matrix initialMg, final Matrix initialGg, final double[] accelerometerBias,
            final Matrix accelerometerMa, final RobustTurntableGyroscopeCalibratorListener listener,
            final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case LMEDS -> new LMedSRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case MSAC -> new MSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case PROSAC -> new PROSACRobustTurntableGyroscopeCalibrator(qualityScores, position, turntableRotationRate,
                    timeInterval, measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg,
                    initialGg, accelerometerBias, accelerometerMa, listener);
            default -> new PROMedSRobustTurntableGyroscopeCalibrator(qualityScores, position, turntableRotationRate,
                    timeInterval, measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg,
                    initialGg, accelerometerBias, accelerometerMa, listener);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param qualityScores                 quality scores corresponding to each provided
     *                                      measurement. The larger the score value the better
     *                                      the quality of the sample.
     * @param position                      position where body kinematics
     *                                      measures have been taken.
     * @param turntableRotationRate         constant rotation rate at which
     *                                      the turntable is spinning. Must
     *                                      be expressed in radians per
     *                                      second (rad/s).
     * @param timeInterval                  time interval between measurements
     *                                      being captured expressed in
     *                                      seconds (s).
     * @param measurements                  collection of body kinematics
     *                                      measurements with standard
     *                                      deviations taken at the same
     *                                      position with zero velocity and
     *                                      unknown different orientations.
     * @param commonAxisUsed                indicates whether z-axis is
     *                                      assumed to be common for
     *                                      accelerometer and gyroscope.
     * @param estimateGDependentCrossBiases true if G-dependent cross biases
     *                                      will be estimated, false
     *                                      otherwise.
     * @param initialBias                   initial gyroscope bias to be
     *                                      used to find a solution. This
     *                                      must be 3x1 and is expressed in
     *                                      radians per second (rad/s).
     * @param initialMg                     initial gyroscope scale factors
     *                                      and cross coupling errors matrix.
     *                                      Must be 3x3.
     * @param initialGg                     initial gyroscope G-dependent
     *                                      cross biases introduced on the
     *                                      gyroscope by the specific forces
     *                                      sensed by the accelerometer. Must
     *                                      be 3x3.
     * @param accelerometerBias             known accelerometer bias. This
     *                                      must have length 3 and is
     *                                      expressed in meters per squared
     *                                      second (m/s^2).
     * @param accelerometerMa               known accelerometer scale factors
     *                                      and cross coupling matrix. Must
     *                                      be 3x3.
     * @param method                        robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size, if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative or
     *                                  if provided quality scores length is
     *                                  smaller than 10 samples.
     */
    public static RobustTurntableGyroscopeCalibrator create(
            final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,

return false;
        }
    }


    /**
     * Gets estimated accelerometer scale factors and ross coupling errors.
     * This is the product of matrix Ta containing cross coupling errors and Ka
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Ka = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Ta = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Ma = [sx    mxy  mxz] = Ta*Ka =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Ma matrix
     * becomes upper diagonal:
     * <pre>
     *     Ma = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated accelerometer scale factors and cross coupling errors, or null
     * if not available.
     */
    @Override
    public Matrix getEstimatedMa() {
        return estimatedMa;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMa != null ? estimatedMa.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMa != null ? estimatedMa.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMa != null ? estimatedMa.getElementAt(2, 1) : null;
    }

return false;
        }
    }

    /**
     * Gets estimated magnetometer soft-iron matrix containing scale factors
     * and cross coupling errors.
     * This is the product of matrix Tm containing cross coupling errors and Km
     * containing scaling factors.
     * So tat:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km
     *          [myx   sy   myz]
     *          [mzx   mzy  sz ]
     * </pre>
     * Where:
     * <pre>
     *     Km = [sx 0   0 ]
     *          [0  sy  0 ]
     *          [0  0   sz]
     * </pre>
     * and
     * <pre>
     *     Tm = [1          -alphaXy    alphaXz ]
     *          [alphaYx    1           -alphaYz]
     *          [-alphaZx   alphaZy     1       ]
     * </pre>
     * Hence:
     * <pre>
     *     Mm = [sx    mxy  mxz] = Tm*Km =  [sx             -sy * alphaXy   sz * alphaXz ]
     *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
     *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
     * </pre>
     * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
     * are considered to be zero if the accelerometer z-axis is assumed to be the same
     * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mm matrix
     * becomes upper diagonal:
     * <pre>
     *     Mm = [sx    mxy  mxz]
     *          [0     sy   myz]
     *          [0     0    sz ]
     * </pre>
     * Values of this matrix are unit-less.
     *
     * @return estimated magnetometer soft-iron scale factors and cross coupling errors,
     * or null if not available.
     */
    @Override
    public Matrix getEstimatedMm() {
        return estimatedMm;
    }

    /**
     * Gets estimated x-axis scale factor.
     *
     * @return estimated x-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSx() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 0) : null;
    }

    /**
     * Gets estimated y-axis scale factor.
     *
     * @return estimated y-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSy() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 1) : null;
    }

    /**
     * Gets estimated z-axis scale factor.
     *
     * @return estimated z-axis scale factor or null if not available.
     */
    @Override
    public Double getEstimatedSz() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 2) : null;
    }

    /**
     * Gets estimated x-y cross-coupling error.
     *
     * @return estimated x-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxy() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 1) : null;
    }

    /**
     * Gets estimated x-z cross-coupling error.
     *
     * @return estimated x-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMxz() {
        return estimatedMm != null ? estimatedMm.getElementAt(0, 2) : null;
    }

    /**
     * Gets estimated y-x cross-coupling error.
     *
     * @return estimated y-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyx() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 0) : null;
    }

    /**
     * Gets estimated y-z cross-coupling error.
     *
     * @return estimated y-z cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMyz() {
        return estimatedMm != null ? estimatedMm.getElementAt(1, 2) : null;
    }

    /**
     * Gets estimated z-x cross-coupling error.
     *
     * @return estimated z-x cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzx() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 0) : null;
    }

    /**
     * Gets estimated z-y cross-coupling error.
     *
     * @return estimated z-y cross-coupling error or null if not available.
     */
    @Override
    public Double getEstimatedMzy() {
        return estimatedMm != null ? estimatedMm.getElementAt(2, 1) : null;
    }

PROSACRobustEasyGyroscopeCalibrator.this, progress);
                }
            }
        });

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            setupAccelerationFixer();

            inliersData = null;
            innerEstimator.setComputeAndKeepInliersEnabled(computeAndKeepInliers || refineResult);
            innerEstimator.setComputeAndKeepResidualsEnabled(computeAndKeepResiduals || refineResult);
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            final var preliminaryResult = innerEstimator.estimate();
            inliersData = innerEstimator.getInliersData();

            attemptRefine(preliminaryResult);

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } catch (final RobustEstimatorException | AlgebraException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROSAC;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement/sequence or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return true;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * This method is used internally and does not check whether instance is
     * locked or not.
     *
     * @param qualityScores quality scores to be set.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than 4 samples.
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores == null || qualityScores.length < EasyGyroscopeCalibrator.MINIMUM_SEQUENCES_COMMON_Z_AXIS) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}

}
    }

    /**
     * Converts a time instance expressed in milliseconds since epoch time
     * (January 1st, 1970 at midnight) to a decimal year.
     *
     * @param timestampMillis milliseconds value to be converted.
     * @return converted value expressed in decimal years.
     */
    private static Double convertTime(final Long timestampMillis) {
        if (timestampMillis == null) {
            return null;
        }

        final var calendar = new GregorianCalendar();
        calendar.setTimeInMillis(timestampMillis);
        return convertTime(calendar);
    }

    /**
     * Converts a time instant contained ina date object to a
     * decimal year.
     *
     * @param date a time instance to be converted.
     * @return converted value expressed in decimal years.
     */
    private static Double convertTime(final Date date) {
        if (date == null) {
            return null;
        }

        final var calendar = new GregorianCalendar();
        calendar.setTime(date);
        return convertTime(calendar);
    }

    /**
     * Converts a time instant contained in a gregorian calendar to a
     * decimal year.
     *
     * @param calendar calendar containing a specific instant to be
     *                 converted.
     * @return converted value expressed in decimal years.
     */
    private static Double convertTime(final GregorianCalendar calendar) {
        if (calendar == null) {
            return null;
        }

        return WMMEarthMagneticFluxDensityEstimator.convertTime(calendar);
    }

    /**
     * Converts provided ECEF position to position expressed in NED
     * coordinates.
     *
     * @param position ECEF position to be converted.
     * @return converted position expressed in NED coordinates.
     */
    private static NEDPosition convertPosition(final ECEFPosition position) {
        final var velocity = new NEDVelocity();
        final var result = new NEDPosition();
        ECEFtoNEDPositionVelocityConverter.convertECEFtoNED(
                position.getX(), position.getY(), position.getZ(),
                0.0, 0.0, 0.0, result, velocity);
        return result;
    }

    /**
     * Converts magnetic flux density value and unit to Teslas.
     *
     * @param value magnetic flux density value.
     * @param unit  unit of magnetic flux density value.
     * @return converted value.
     */
    private static double convertMagneticFluxDensity(final double value, final MagneticFluxDensityUnit unit) {
        return MagneticFluxDensityConverter.convert(value, unit, MagneticFluxDensityUnit.TESLA);
    }

    /**
     * Converts magnetic flux density instance to Teslas.
     *
     * @param magneticFluxDensity magnetic flux density instance to be converted.
     * @return converted value.
     */
    private static double convertMagneticFluxDensity(final MagneticFluxDensity magneticFluxDensity) {
        return convertMagneticFluxDensity(magneticFluxDensity.getValue().doubleValue(), magneticFluxDensity.getUnit());
    }

this.biasZ = convertAcceleration(biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @return known accelerometer bias.
     */
    @Override
    public AccelerationTriad getBiasAsTriad() {
        return new AccelerationTriad(AccelerationUnit.METERS_PER_SQUARED_SECOND, biasX, biasY, biasZ);
    }

    /**
     * Gets known accelerometer bias.
     *
     * @param result instance where result will be stored.
     */
    @Override
    public void getBiasAsTriad(final AccelerationTriad result) {
        result.setValueCoordinatesAndUnit(biasX, biasY, biasZ, AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Sets known accelerometer bias.
     *
     * @param bias accelerometer bias to be set.
     * @throws LockedException if calibrator is currently running.
     */
    @Override
    public void setBias(final AccelerationTriad bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

        biasX = convertAcceleration(bias.getValueX(), bias.getUnit());
        biasY = convertAcceleration(bias.getValueY(), bias.getUnit());
        biasZ = convertAcceleration(bias.getValueZ(), bias.getUnit());
    }

    /**
     * Gets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @return array containing coordinates of known bias.
     */
    @Override
    public double[] getBias() {
        final var result = new double[BodyKinematics.COMPONENTS];
        getBias(result);
        return result;
    }

    /**
     * Gets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param result instance where result data will be copied to.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void getBias(final double[] result) {
        if (result.length != BodyKinematics.COMPONENTS) {
            throw new IllegalArgumentException();
        }
        result[0] = biasX;
        result[1] = biasY;
        result[2] = biasZ;
    }

    /**
     * Sets known accelerometer bias as an array.
     * Array values are expressed in meters per squared second (m/s^2).
     *
     * @param bias known accelerometer bias.
     * @throws LockedException          if calibrator is currently running.
     * @throws IllegalArgumentException if provided array does not have length 3.
     */
    @Override
    public void setBias(final double[] bias) throws LockedException {
        if (running) {
            throw new LockedException();
        }

PROSACRobustKnownFrameMagnetometerCalibrator.this, progress);
                }
            }
        });

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            inliersData = null;

            setupWmmEstimator();

            innerEstimator.setComputeAndKeepInliersEnabled(computeAndKeepInliers || refineResult);
            innerEstimator.setComputeAndKeepResidualsEnabled(computeAndKeepResiduals || refineResult);
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            final var preliminaryResult = innerEstimator.estimate();
            inliersData = innerEstimator.getInliersData();

            attemptRefine(preliminaryResult);

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } catch (final RobustEstimatorException | IOException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROSAC;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return true;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * This method is used internally and does not check whether instance is
     * locked or not.
     *
     * @param qualityScores quality scores to be set.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than 4 samples.
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores == null || qualityScores.length < MINIMUM_MEASUREMENTS) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}

PROSACRobustKnownHardIronPositionAndInstantMagnetometerCalibrator.this, progress);
                }
            }
        });

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            inliersData = null;

            initialize();

            innerEstimator.setComputeAndKeepInliersEnabled(computeAndKeepInliers || refineResult);
            innerEstimator.setComputeAndKeepResidualsEnabled(computeAndKeepResiduals || refineResult);
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            final var preliminaryResult = innerEstimator.estimate();
            inliersData = innerEstimator.getInliersData();

            attemptRefine(preliminaryResult);

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } catch (final RobustEstimatorException | IOException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROSAC;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return true;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * This method is used internally and does not check whether instance is
     * locked or not.
     *
     * @param qualityScores quality scores to be set.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than 4 samples.
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores == null || qualityScores.length < MINIMUM_MEASUREMENTS_COMMON_Z_AXIS) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}

public void setListener(final KnownFrameMagnetometerNonLinearLeastSquaresCalibratorListener listener)
            throws LockedException {
        if (running) {
            throw new LockedException();
        }

        this.listener = listener;
    }

    /**
     * Gets minimum number of required measurements.
     *
     * @return minimum number of required measurements.
     */
    @Override
    public int getMinimumRequiredMeasurements() {
        return MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is ready to start the estimator.
     *
     * @return true if calibrator is ready, false otherwise.
     */
    @Override
    public boolean isReady() {
        return measurements != null && measurements.size() >= MINIMUM_MEASUREMENTS;
    }

    /**
     * Indicates whether calibrator is currently running or no.
     *
     * @return true if calibrator is running, false otherwise.
     */
    @Override
    public boolean isRunning() {
        return running;
    }

    /**
     * Gets Earth's magnetic model.
     *
     * @return Earth's magnetic model or null if not provided.
     */
    public WorldMagneticModel getMagneticModel() {
        return magneticModel;
    }

    /**
     * Sets Earth's magnetic model.
     *
     * @param magneticModel Earth's magnetic model to be set.
     * @throws LockedException if calibrator is currently running.
     */
    public void setMagneticModel(final WorldMagneticModel magneticModel) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        this.magneticModel = magneticModel;
    }

    /**
     * Estimates magnetometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if calibration fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }

        if (!isReady()) {
            throw new NotReadyException();
        }

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            if (commonAxisUsed) {
                calibrateCommonAxis();
            } else {
                calibrateGeneral();
            }

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final AlgebraException | FittingException | com.irurueta.numerical.NotReadyException | IOException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Gets array containing x,y,z components of estimated magnetometer
     * hard-iron biases expressed in Teslas (T).
     *
     * @return array containing x,y,z components of estimated magnetometer
     * hard-iron biases.
     */
    @Override
    public double[] getEstimatedHardIron() {

PROSACRobustKnownBiasAndGravityNormAccelerometerCalibrator.this, progress);
                }
            }
        });

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            inliersData = null;
            innerEstimator.setComputeAndKeepInliersEnabled(computeAndKeepInliers || refineResult);
            innerEstimator.setComputeAndKeepResidualsEnabled(computeAndKeepResiduals || refineResult);
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            final var preliminaryResult = innerEstimator.estimate();
            inliersData = innerEstimator.getInliersData();

            attemptRefine(preliminaryResult);

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } catch (final RobustEstimatorException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROSAC;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return true;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * This method is used internally and does not check whether instance is
     * locked or not.
     *
     * @param qualityScores quality scores to be set.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than the minimum required
     *                                  number of samples (10 or 13).
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores == null || qualityScores.length < getMinimumRequiredMeasurements()) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}

super(sequences, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                accelerometerBias, accelerometerMa, listener);
    }

    /**
     * Returns threshold to determine whether samples are inliers or not.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not.
     *
     * @param threshold threshold to be set.
     * @throws IllegalArgumentException if provided value is equal or less than
     *                                  zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Estimates gyroscope calibration parameters containing bias, scale factors,
     * cross-coupling errors and G-dependent coupling.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new MSACRobustEstimator<>(new MSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return sequences.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(sequences.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return MSACRobustEasyGyroscopeCalibrator.super.isReady();

super(groundTruthMagneticFluxDensityNorm, measurements, commonAxisUsed, initialHardIron, initialMm, listener);
    }

    /**
     * Returns threshold to determine whether samples are inliers or not.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not.
     *
     * @param threshold threshold to be set.
     * @throws IllegalArgumentException if provided value is equal or less than
     *                                  zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Estimates magnetometer calibration parameters containing hard-iron
     * bias and soft-iron scale factors and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new MSACRobustEstimator<>(new MSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return MSACRobustKnownMagneticFluxDensityNormMagnetometerCalibrator.super.isReady();

final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final Speed vx, final Speed vy, final Speed vz, final Speed oldVx, final Speed oldVy, final Speed oldVz,
            final double x, final double y, final double z, final BodyKinematics result) {
        estimateKinematics(timeInterval, c, oldC,
                SpeedConverter.convert(vx.getValue().doubleValue(), vx.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(vy.getValue().doubleValue(), vy.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(vz.getValue().doubleValue(), vz.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVx.getValue().doubleValue(), oldVx.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVy.getValue().doubleValue(), oldVy.getUnit(), SpeedUnit.METERS_PER_SECOND),
                SpeedConverter.convert(oldVz.getValue().doubleValue(), oldVz.getUnit(), SpeedUnit.METERS_PER_SECOND),
                x, y, z, result);
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs.
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param result       instance where body kinematics estimation will be stored.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static void estimateKinematics(
            final Time timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,

}

    /**
     * Sets input data into Levenberg-Marquardt fitter.
     *
     * @throws WrongSizeException never happens.
     */
    private void setInputData() throws WrongSizeException {

        final var g = groundTruthGravityNorm;
        final var g2 = g * g;

        final var numMeasurements = measurements.size();
        final var x = new Matrix(numMeasurements, BodyKinematics.COMPONENTS);
        final var y = new double[numMeasurements];
        final var specificForceStandardDeviations = new double[numMeasurements];
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredKinematics = measurement.getKinematics();

            final var fx = measuredKinematics.getFx();
            final var fy = measuredKinematics.getFy();
            final var fz = measuredKinematics.getFz();

            x.setElementAt(i, 0, fx);
            x.setElementAt(i, 1, fy);
            x.setElementAt(i, 2, fz);

            y[i] = g2;

            specificForceStandardDeviations[i] = measurement.getSpecificForceStandardDeviation();

            i++;
        }

        fitter.setInputData(x, y, specificForceStandardDeviations);
    }

    /**
     * Internal method to perform general calibration.
     *
     * @throws FittingException                         if Levenberg-Marquardt fails for numerical reasons.
     * @throws AlgebraException                         if there are numerical instabilities that prevent
     *                                                  matrix inversion.
     * @throws com.irurueta.numerical.NotReadyException never happens.
     */
    private void calibrateGeneral() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {
        // The accelerometer model is:
        // fmeas = ba + (I + Ma) * ftrue + w

        // Ideally a least squares solution tries to minimize noise component, so:
        // fmeas = ba + (I + Ma) * ftrue

        // For convergence purposes of the Levenberg-Marquardt algorithm, the
        // accelerometer model can be better expressed as:
        // fmeas = T*K*(ftrue + b)
        // fmeas = M*(ftrue + b)
        // fmeas = M*ftrue + M*b

        // where:
        // M = I + Ma
        // ba = M*b = (I + Ma)*b --> b = M^-1*ba

        // We know that the norm of the true specific force is equal to the amount
        // of gravity at a certain Earth position
        // ||ftrue|| = ||g|| ~ 9.81 m/s^2

        // Hence:
        // fmeas - M*b = M*ftrue

        // M^-1 * (fmeas - M*b) = ftrue

        // ||g||^2 = ||ftrue||^2 = (M^-1 * (fmeas - M*b))^T * (M^-1 * (fmeas - M*b))
        // ||g||^2 = (fmeas - M*b)^T*(M^-1)^T * M^-1 * (fmeas - M*b)
        // ||g||^2 = (fmeas - M * b)^T * ||M^-1||^2 * (fmeas - M * b)
        // ||g||^2 = ||fmeas - M * b||^2 * ||M^-1||^2

        // Where:

        // b = [bx]
        //     [by]
        //     [bz]

        // M = [m11 	m12 	m13]
        //     [m21 	m22 	m23]
        //     [m31 	m32 	m33]

        // Notice that bias b is known, hence only terms in matrix M need to be estimated

        final var gradientEstimator = new GradientEstimator(this::evaluateGeneral);

        final var initialM = Matrix.identity(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
        initialM.add(getInitialMa());

super(position, measurements, commonAxisUsed, bias, initialMa, listener);
    }

    /**
     * Returns threshold to determine whether samples are inliers or not.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not.
     *
     * @param threshold threshold to be set.
     * @throws IllegalArgumentException if provided value is equal or less than
     *                                  zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Estimates accelerometer calibration parameters containing scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        gravityNorm = computeGravityNorm();

        final var innerEstimator = new MSACRobustEstimator<>(new MSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return MSACRobustKnownBiasAndPositionAccelerometerCalibrator.super.isReady();

PROSACRobustKnownBiasAndFrameAccelerometerCalibrator.this, progress);
                }
            }
        });

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            inliersData = null;
            innerEstimator.setComputeAndKeepInliersEnabled(computeAndKeepInliers || refineResult);
            innerEstimator.setComputeAndKeepResidualsEnabled(computeAndKeepResiduals || refineResult);
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            final var preliminaryResult = innerEstimator.estimate();
            inliersData = innerEstimator.getInliersData();

            attemptRefine(preliminaryResult);

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } catch (final RobustEstimatorException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROSAC;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return true;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * This method is used internally and does not check whether instance is
     * locked or not.
     *
     * @param qualityScores quality scores to be set.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than 4 samples.
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores == null || qualityScores.length < MINIMUM_MEASUREMENTS) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}

PROSACRobustKnownHardIronMagneticFluxDensityNormMagnetometerCalibrator.this,
                            progress);
                }
            }
        });

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            inliersData = null;

            innerEstimator.setComputeAndKeepInliersEnabled(computeAndKeepInliers || refineResult);
            innerEstimator.setComputeAndKeepResidualsEnabled(computeAndKeepResiduals || refineResult);
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            final var preliminaryResult = innerEstimator.estimate();
            inliersData = innerEstimator.getInliersData();

            attemptRefine(preliminaryResult);

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } catch (final RobustEstimatorException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROSAC;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return true;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * This method is used internally and does not check whether instance is
     * locked or not.
     *
     * @param qualityScores quality scores to be set.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than 4 samples.
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores == null || qualityScores.length < MINIMUM_MEASUREMENTS_COMMON_Z_AXIS) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}

final ECEFPosition position, final double turntableRotationRate, final double timeInterval,
            final List<StandardDeviationBodyKinematics> measurements, final boolean commonAxisUsed,
            final boolean estimateGDependentCrossBiases, final double[] bias, final Matrix initialMg,
            final Matrix initialGg, final double[] accelerometerBias, final Matrix accelerometerMa,
            final RobustKnownBiasTurntableGyroscopeCalibratorListener listener, final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case LMEDS -> new LMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case MSAC -> new MSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case PROSAC -> new PROSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            default -> new PROMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param position                      position where body kinematics
     *                                      measures have been taken.
     * @param turntableRotationRate         constant rotation rate at which
     *                                      the turntable is spinning. Must
     *                                      be expressed in radians per
     *                                      second (rad/s).
     * @param timeInterval                  time interval between measurements
     *                                      being captured expressed in
     *                                      seconds (s).
     * @param measurements                  collection of body kinematics
     *                                      measurements with standard
     *                                      deviations taken at the same
     *                                      position with zero velocity and
     *                                      unknown different orientations.
     * @param commonAxisUsed                indicates whether z-axis is
     *                                      assumed to be common for
     *                                      accelerometer and gyroscope.
     * @param estimateGDependentCrossBiases true if G-dependent cross biases
     *                                      will be estimated, false
     *                                      otherwise.
     * @param bias                          known gyroscope bias. This
     *                                      must be 3x1 and is expressed in
     *                                      radians per second (rad/s).
     * @param initialMg                     initial gyroscope scale factors
     *                                      and cross coupling errors matrix.
     *                                      Must be 3x3.
     * @param initialGg                     initial gyroscope G-dependent
     *                                      cross biases introduced on the
     *                                      gyroscope by the specific forces
     *                                      sensed by the accelerometer. Must
     *                                      be 3x3.
     * @param accelerometerBias             known accelerometer bias. This
     *                                      must have length 3 and is
     *                                      expressed in meters per squared
     *                                      second (m/s^2).
     * @param accelerometerMa               known accelerometer scale factors
     *                                      and cross coupling matrix. Must
     *                                      be 3x3.
     * @param method                        robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size or if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative.
     */
    public static RobustKnownBiasTurntableGyroscopeCalibrator create(
            final ECEFPosition position, final double turntableRotationRate, final double timeInterval,

final ECEFPosition position, final double turntableRotationRate, final double timeInterval,
            final List<StandardDeviationBodyKinematics> measurements, final boolean commonAxisUsed,
            final boolean estimateGDependentCrossBiases, final double[] initialBias, final Matrix initialMg,
            final Matrix initialGg, final double[] accelerometerBias, final Matrix accelerometerMa,
            final RobustTurntableGyroscopeCalibratorListener listener, final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case LMEDS -> new LMedSRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case MSAC -> new MSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case PROSAC -> new PROSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            default -> new PROMedSRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param position                      position where body kinematics
     *                                      measures have been taken.
     * @param turntableRotationRate         constant rotation rate at which
     *                                      the turntable is spinning. Must
     *                                      be expressed in radians per
     *                                      second (rad/s).
     * @param timeInterval                  time interval between measurements
     *                                      being captured expressed in
     *                                      seconds (s).
     * @param measurements                  collection of body kinematics
     *                                      measurements with standard
     *                                      deviations taken at the same
     *                                      position with zero velocity and
     *                                      unknown different orientations.
     * @param commonAxisUsed                indicates whether z-axis is
     *                                      assumed to be common for
     *                                      accelerometer and gyroscope.
     * @param estimateGDependentCrossBiases true if G-dependent cross biases
     *                                      will be estimated, false
     *                                      otherwise.
     * @param initialBias                   initial gyroscope bias to be
     *                                      used to find a solution. This
     *                                      must be 3x1 and is expressed in
     *                                      radians per second (rad/s).
     * @param initialMg                     initial gyroscope scale factors
     *                                      and cross coupling errors matrix.
     *                                      Must be 3x3.
     * @param initialGg                     initial gyroscope G-dependent
     *                                      cross biases introduced on the
     *                                      gyroscope by the specific forces
     *                                      sensed by the accelerometer. Must
     *                                      be 3x3.
     * @param accelerometerBias             known accelerometer bias. This
     *                                      must have length 3 and is
     *                                      expressed in meters per squared
     *                                      second (m/s^2).
     * @param accelerometerMa               known accelerometer scale factors
     *                                      and cross coupling matrix. Must
     *                                      be 3x3.
     * @param method                        robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size or if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative.
     */
    public static RobustTurntableGyroscopeCalibrator create(
            final ECEFPosition position, final double turntableRotationRate, final double timeInterval,

private void setInputData() throws WrongSizeException {
        final var gtb = groundTruthMagneticFluxDensityNorm;
        final var gtb2 = gtb * gtb;

        final var numMeasurements = measurements.size();
        final var x = new Matrix(numMeasurements, BodyMagneticFluxDensity.COMPONENTS);
        final var y = new double[numMeasurements];
        final var specificForceStandardDeviations = new double[numMeasurements];
        var i = 0;
        for (final var measurement : measurements) {
            final var measuredMagneticFluxDensity = measurement.getMagneticFluxDensity();

            final var bmeasuredX = measuredMagneticFluxDensity.getBx();
            final var bmeasuredY = measuredMagneticFluxDensity.getBy();
            final var bmeasuredZ = measuredMagneticFluxDensity.getBz();

            x.setElementAt(i, 0, bmeasuredX);
            x.setElementAt(i, 1, bmeasuredY);
            x.setElementAt(i, 2, bmeasuredZ);

            y[i] = gtb2;

            specificForceStandardDeviations[i] = measurement.getMagneticFluxDensityStandardDeviation();

            i++;
        }

        fitter.setInputData(x, y, specificForceStandardDeviations);
    }

    /**
     * Internal method to perform general calibration.
     *
     * @throws FittingException                         if Levenberg-Marquardt fails for numerical reasons.
     * @throws AlgebraException                         if there are numerical instabilities that prevent
     *                                                  matrix inversion.
     * @throws com.irurueta.numerical.NotReadyException never happens.
     */
    private void calibrateGeneral() throws AlgebraException, FittingException,
            com.irurueta.numerical.NotReadyException {
        // The magnetometer model is:
        // bmeas = bm + (I + Mm) * btrue + w

        // Ideally a least squares solution tries to minimize noise component, so:
        // bmeas = bm + (I + Mm) * btrue

        // For convergence purposes of the Levenberg-Marquardt algorithm, the
        // magnetometer model can be better expressed as:
        // bmeas = T*K*(btrue + b)
        // bmeas = M*(btrue + b)
        // bmeas = M*btrue + M*b

        // where:
        // M = I + Mm
        // bm = M*b = (I + Mm)*b --> b = M^-1*bm

        // We know that the norm of the true body magnetic flux density
        // is equal to the amount of Earth magnetic flux density at provided
        // position and timestamp
        // ||btrue|| = ||bEarth|| --> from 30 µT to 60 µT

        // Hence:
        // bmeas - M*b = M*btrue

        // M^-1 * (bmeas - M*b) = btrue

        // ||bEarth||^2 = ||btrue||^2 = (M^-1 * (bmeas - M*b))^T * (M^-1 * (bmeas - M*b))
        // ||bEarth||^2 = (bmeas - M*b)^T*(M^-1)^T * M^-1 * (bmeas - M*b)
        // ||bEarth||^2 = (bmeas - M * b)^T * ||M^-1||^2 * (bmeas - M * b)
        // ||bEarth||^2 = ||bmeas - M * b||^2 * ||M^-1||^2

        // Where:

        // b = [bx]
        //     [by]
        //     [bz]

        // M = [m11 	m12 	m13]
        //     [m21 	m22 	m23]
        //     [m31 	m32 	m33]

        final var gradientEstimator = new GradientEstimator(this::evaluateGeneral);

        final var initialM = Matrix.identity(BodyMagneticFluxDensity.COMPONENTS, BodyMagneticFluxDensity.COMPONENTS);
        initialM.add(getInitialMm());

final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,
            final double timeInterval, final List<StandardDeviationBodyKinematics> measurements,
            final boolean commonAxisUsed, final boolean estimateGDependentCrossBiases, final Matrix bias,
            final Matrix initialMg, final Matrix initialGg, final Matrix accelerometerBias,
            final Matrix accelerometerMa, final RobustKnownBiasTurntableGyroscopeCalibratorListener listener,
            final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case LMEDS -> new LMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case MSAC -> new MSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case PROSAC -> new PROSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    qualityScores, position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            default -> new PROMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    qualityScores, position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param qualityScores         quality scores corresponding to each provided
     *                              measurement. The larger the score value the better
     *                              the quality of the sample.
     * @param position              position where body kinematics measures
     *                              have been taken.
     * @param turntableRotationRate constant rotation rate at which the
     *                              turntable is spinning. Must be
     *                              expressed in radians per second (rad/s).
     * @param timeInterval          time interval between measurements being
     *                              captured expressed in seconds (s).
     * @param measurements          collection of body kinematics
     *                              measurements with standard deviations
     *                              taken at the same position with zero
     *                              velocity and unknown different
     *                              orientations.
     * @param bias                  known gyroscope bias. This must be 3x1 and
     *                              is expressed in radians per second
     *                              (rad/s).
     * @param initialMg             initial gyroscope scale factors and
     *                              cross coupling errors matrix. Must
     *                              be 3x3.
     * @param initialGg             initial gyroscope G-dependent cross
     *                              biases introduced on the gyroscope by
     *                              the specific forces sensed by the
     *                              accelerometer. Must be 3x3.
     * @param method                robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size, if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative or
     *                                  if provided quality scores length is
     *                                  smaller than 7 samples.
     */
    public static RobustKnownBiasTurntableGyroscopeCalibrator create(

final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,
            final double timeInterval, final List<StandardDeviationBodyKinematics> measurements,
            final boolean commonAxisUsed, final boolean estimateGDependentCrossBiases, final Matrix initialBias,
            final Matrix initialMg, final Matrix initialGg, final Matrix accelerometerBias,
            final Matrix accelerometerMa, final RobustTurntableGyroscopeCalibratorListener listener,
            final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case LMEDS -> new LMedSRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case MSAC -> new MSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case PROSAC -> new PROSACRobustTurntableGyroscopeCalibrator(qualityScores, position, turntableRotationRate,
                    timeInterval, measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg,
                    initialGg, accelerometerBias, accelerometerMa, listener);
            default -> new PROMedSRobustTurntableGyroscopeCalibrator(qualityScores, position, turntableRotationRate,
                    timeInterval, measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg,
                    initialGg, accelerometerBias, accelerometerMa, listener);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param qualityScores         quality scores corresponding to each provided
     *                              measurement. The larger the score value the better
     *                              the quality of the sample.
     * @param position              position where body kinematics measures
     *                              have been taken.
     * @param turntableRotationRate constant rotation rate at which the
     *                              turntable is spinning. Must be
     *                              expressed in radians per second (rad/s).
     * @param timeInterval          time interval between measurements being
     *                              captured expressed in seconds (s).
     * @param measurements          collection of body kinematics
     *                              measurements with standard deviations
     *                              taken at the same position with zero
     *                              velocity and unknown different
     *                              orientations.
     * @param initialBias           initial gyroscope bias to be used to
     *                              find a solution. This must be 3x1 and
     *                              is expressed in radians per second
     *                              (rad/s).
     * @param initialMg             initial gyroscope scale factors and
     *                              cross coupling errors matrix. Must
     *                              be 3x3.
     * @param initialGg             initial gyroscope G-dependent cross
     *                              biases introduced on the gyroscope by
     *                              the specific forces sensed by the
     *                              accelerometer. Must be 3x3.
     * @param method                robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size, if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative or
     *                                  if provided quality scores length is
     *                                  smaller than 10 samples.
     */
    public static RobustTurntableGyroscopeCalibrator create(

final Time timeInterval, final ECEFFrame frame, final ECEFFrame oldFrame) {
        final var result = new BodyKinematics();
        estimateKinematics(timeInterval, frame, oldFrame, result);
        return result;
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @return a new body kinematics instance.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static BodyKinematics estimateKinematicsAndReturnNew(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final Speed vx, final Speed vy, final Speed vz, final Speed oldVx, final Speed oldVy, final Speed oldVz,
            final double x, final double y, final double z) {
        final var result = new BodyKinematics();
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz, x, y, z, result);
        return result;
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs.
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param x            cartesian x coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param y            cartesian y coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @param z            cartesian z coordinate of body position expressed in meters (m)
     *                     with respect ECEF frame, resolved along ECEF-frame axes.
     * @return a new body kinematics instance.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static BodyKinematics estimateKinematicsAndReturnNew(
            final Time timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,
            final Speed vx, final Speed vy, final Speed vz, final Speed oldVx, final Speed oldVy, final Speed oldVz,
            final double x, final double y, final double z) {
        final var result = new BodyKinematics();
        estimateKinematics(timeInterval, c, oldC, vx, vy, vz, oldVx, oldVy, oldVz, x, y, z, result);
        return result;
    }

    /**
     * Estimates body kinematics (specific force applied to a body and its angular rates).
     *
     * @param timeInterval time interval between epochs expressed in seconds (s).
     * @param c            body-to-ECEF frame coordinate transformation matrix.
     * @param oldC         previous body-to-ECEF-frame coordinate transformation matrix.
     * @param vx           velocity of body frame x coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vy           velocity of body frame y coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param vz           velocity of body frame z coordinate with respect ECEF frame,
     *                     resolved along ECEF-frame axes.
     * @param oldVx        previous velocity of body frame x coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVy        previous velocity of body frame y coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param oldVz        previous velocity of body frame z coordinate with respect ECEF
     *                     frame, resolved along ECEF-frame axes.
     * @param position     cartesian body position resolved along ECEF-frame axes.
     * @return a new body kinematics instance.
     * @throws IllegalArgumentException if provided time interval is negative or coordinated transformation matrices
     *                                  are not ECEF frame valid.
     */
    public static BodyKinematics estimateKinematicsAndReturnNew(
            final double timeInterval, final CoordinateTransformation c, final CoordinateTransformation oldC,

estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                listener);
    }

    /**
     * Returns threshold to determine whether samples are inliers or not.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not.
     *
     * @param threshold threshold to be set.
     * @throws IllegalArgumentException if provided value is equal or less than
     *                                  zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Estimates gyroscope calibration parameters containing scale factors
     * cross-coupling errors and g-dependant cross biases.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new MSACRobustEstimator<>(new MSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return MSACRobustKnownBiasTurntableGyroscopeCalibrator.super.isReady();

PROMedSRobustEasyGyroscopeCalibrator.this, progress);
                        }
                    }
                });

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            setupAccelerationFixer();

            inliersData = null;
            innerEstimator.setUseInlierThresholds(true);
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            final var preliminaryResult = innerEstimator.estimate();
            inliersData = innerEstimator.getInliersData();

            attemptRefine(preliminaryResult);

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } catch (final RobustEstimatorException | AlgebraException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROMEDS;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement/sequence or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return true;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * This method is used internally and does not check whether instance is
     * locked or not.
     *
     * @param qualityScores quality scores to be set.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than 4 samples.
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores == null
                || qualityScores.length < TurntableGyroscopeCalibrator.MINIMUM_MEASUREMENTS_COMMON_Z_AXIS) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}

estimatedMg = preliminaryResult.estimatedMg;
            estimatedGg = preliminaryResult.estimatedGg;
            estimatedMse = preliminaryResult.estimatedMse;
            estimatedChiSq = preliminaryResult.estimatedChiSq;
        }
    }

    /**
     * Converts provided NED position expressed in terms of latitude, longitude and height respect
     * mean Earth surface, to position expressed in ECEF coordinates.
     *
     * @param position NED position to be converted.
     * @return converted position expressed in ECEF coordinates.
     */
    private static ECEFPosition convertPosition(final NEDPosition position) {
        final var velocity = new ECEFVelocity();
        final var result = new ECEFPosition();
        NEDtoECEFPositionVelocityConverter.convertNEDtoECEF(
                position.getLatitude(), position.getLongitude(), position.getHeight(),
                0.0, 0.0, 0.0, result, velocity);
        return result;
    }

    /**
     * Converts acceleration instance to meters per squared second.
     *
     * @param acceleration acceleration instance to be converted.
     * @return converted value.
     */
    private static double convertAcceleration(final Acceleration acceleration) {
        return AccelerationConverter.convert(acceleration.getValue().doubleValue(), acceleration.getUnit(),
                AccelerationUnit.METERS_PER_SQUARED_SECOND);
    }

    /**
     * Converts angular speed instance to radians per second (rad/s).
     *
     * @param value angular speed value.
     * @param unit  unit of angular speed value.
     * @return converted value.
     */
    private static double convertAngularSpeed(final double value, final AngularSpeedUnit unit) {
        return AngularSpeedConverter.convert(value, unit, AngularSpeedUnit.RADIANS_PER_SECOND);
    }

    /**
     * Converts angular speed instance to radians per second (rad/s).
     *
     * @param angularSpeed angular speed instance to be converted.
     * @return converted value.
     */
    private static double convertAngularSpeed(final AngularSpeed angularSpeed) {
        return convertAngularSpeed(angularSpeed.getValue().doubleValue(), angularSpeed.getUnit());
    }

    /**
     * Converts time instance to seconds.
     *
     * @param time time instance to be converted.
     * @return converted value.
     */
    private static double convertTime(final Time time) {
        return TimeConverter.convert(time.getValue().doubleValue(), time.getUnit(), TimeUnit.SECOND);
    }

    /**
     * Internal class containing estimated preliminary result.
     */
    protected static class PreliminaryResult {
        /**
         * Estimated gyroscope scale factors and cross coupling errors.
         * This is the product of matrix Tg containing cross coupling errors and Kg
         * containing scaling factors.
         * So that:
         * <pre>
         *     Mg = [sx    mxy  mxz] = Tg*Kg
         *          [myx   sy   myz]
         *          [mzx   mzy  sz ]
         * </pre>
         * Where:
         * <pre>
         *     Kg = [sx 0   0 ]
         *          [0  sy  0 ]
         *          [0  0   sz]
         * </pre>
         * and
         * <pre>
         *     Tg = [1          -alphaXy    alphaXz ]
         *          [alphaYx    1           -alphaYz]
         *          [-alphaZx   alphaZy     1       ]
         * </pre>
         * Hence:
         * <pre>
         *     Mg = [sx    mxy  mxz] = Tg*Kg =  [sx             -sy * alphaXy   sz * alphaXz ]
         *          [myx   sy   myz]            [sx * alphaYx   sy              -sz * alphaYz]
         *          [mzx   mzy  sz ]            [-sx * alphaZx  sy * alphaZy    sz           ]
         * </pre>
         * This instance allows any 3x3 matrix however, typically alphaYx, alphaZx and alphaZy
         * are considered to be zero if the gyroscope z-axis is assumed to be the same
         * as the body z-axis. When this is assumed, myx = mzx = mzy = 0 and the Mg matrix
         * becomes upper diagonal:
         * <pre>
         *     Mg = [sx    mxy  mxz]
         *          [0     sy   myz]
         *          [0     0    sz ]
         * </pre>
         * Values of this matrix are unit-less.
         */
        private Matrix estimatedMg;

super(groundTruthGravityNorm, measurements, commonAxisUsed, bias, initialMa, listener);
    }

    /**
     * Returns threshold to determine whether samples are inliers or not.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not.
     *
     * @param threshold threshold to be set.
     * @throws IllegalArgumentException if provided value is equal or less than
     *                                  zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Estimates accelerometer calibration parameters containing bias, scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new MSACRobustEstimator<>(new MSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return MSACRobustKnownBiasAndGravityNormAccelerometerCalibrator.super.isReady();

super(measurements, commonAxisUsed, listener);
    }

    /**
     * Returns threshold to determine whether samples are inliers or not.
     *
     * @return threshold to determine whether samples are inliers or not.
     */
    public double getThreshold() {
        return threshold;
    }

    /**
     * Sets threshold to determine whether samples are inliers or not.
     *
     * @param threshold threshold to be set.
     * @throws IllegalArgumentException if provided value is equal or less than
     *                                  zero.
     * @throws LockedException          if calibrator is currently running.
     */
    public void setThreshold(final double threshold) throws LockedException {
        if (running) {
            throw new LockedException();
        }
        if (threshold <= MIN_THRESHOLD) {
            throw new IllegalArgumentException();
        }
        this.threshold = threshold;
    }

    /**
     * Estimates accelerometer calibration parameters containing bias, scale factors
     * and cross-coupling errors.
     *
     * @throws LockedException      if calibrator is currently running.
     * @throws NotReadyException    if calibrator is not ready.
     * @throws CalibrationException if estimation fails for numerical reasons.
     */
    @SuppressWarnings("DuplicatedCode")
    @Override
    public void calibrate() throws LockedException, NotReadyException, CalibrationException {
        if (running) {
            throw new LockedException();
        }
        if (!isReady()) {
            throw new NotReadyException();
        }

        final var innerEstimator = new MSACRobustEstimator<>(new MSACRobustEstimatorListener<PreliminaryResult>() {
            @Override
            public double getThreshold() {
                return threshold;
            }

            @Override
            public int getTotalSamples() {
                return measurements.size();
            }

            @Override
            public int getSubsetSize() {
                return preliminarySubsetSize;
            }

            @Override
            public void estimatePreliminarSolutions(
                    final int[] samplesIndices, final List<PreliminaryResult> solutions) {
                computePreliminarySolutions(samplesIndices, solutions);
            }

            @Override
            public double computeResidual(final PreliminaryResult currentEstimation, final int i) {
                return computeError(measurements.get(i), currentEstimation);
            }

            @Override
            public boolean isReady() {
                return MSACRobustKnownFrameAccelerometerCalibrator.super.isReady();

final int i, final double bx, final double by, final double bz,
            final double m11, final double m21, final double m31,
            final double m12, final double m22, final double m32,
            final double m13, final double m23, final double m33,
            final double g11, final double g21, final double g31,
            final double g12, final double g22, final double g32,
            final double g13, final double g23, final double g33) throws EvaluationException {

        try {
            final var measuredSequence = sequences.get(i);
            final var fixedSequence = fixedSequences.get(i);

            // generate new sequence using current parameters to fix angular rate measurements
            if (measuredSpecificForce == null) {
                measuredSpecificForce = new Matrix(BodyKinematics.COMPONENTS, 1);
            }
            if (trueSpecificForce == null) {
                trueSpecificForce = new Matrix(BodyKinematics.COMPONENTS, 1);
            }

            if (measuredAngularRate == null) {
                measuredAngularRate = new Matrix(BodyKinematics.COMPONENTS, 1);
            }
            if (trueAngularRate == null) {
                trueAngularRate = new Matrix(BodyKinematics.COMPONENTS, 1);
            }

            if (m == null) {
                m = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }
            if (invM == null) {
                invM = new Matrix(BodyKinematics.COMPONENTS, BodyKinematics.COMPONENTS);
            }
            if (b == null) {

final ECEFPosition position, final double turntableRotationRate, final double timeInterval,
            final List<StandardDeviationBodyKinematics> measurements, final boolean commonAxisUsed,
            final boolean estimateGDependentCrossBiases, final Matrix bias, final Matrix initialMg,
            final Matrix initialGg, final Matrix accelerometerBias, final Matrix accelerometerMa,
            final RobustKnownBiasTurntableGyroscopeCalibratorListener listener, final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case LMEDS -> new LMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case MSAC -> new MSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            case PROSAC -> new PROSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
            default -> new PROMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa,
                    listener);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param position              position where body kinematics measures
     *                              have been taken.
     * @param turntableRotationRate constant rotation rate at which the
     *                              turntable is spinning. Must be
     *                              expressed in radians per second (rad/s).
     * @param timeInterval          time interval between measurements being
     *                              captured expressed in seconds (s).
     * @param measurements          collection of body kinematics
     *                              measurements with standard deviations
     *                              taken at the same position with zero
     *                              velocity and unknown different
     *                              orientations.
     * @param bias                  known gyroscope bias. This must be 3x1 and
     *                              is expressed in radians per second
     *                              (rad/s).
     * @param initialMg             initial gyroscope scale factors and
     *                              cross coupling errors matrix. Must
     *                              be 3x3.
     * @param initialGg             initial gyroscope G-dependent cross
     *                              biases introduced on the gyroscope by
     *                              the specific forces sensed by the
     *                              accelerometer. Must be 3x3.
     * @param method                robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size or if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative.
     */
    public static RobustKnownBiasTurntableGyroscopeCalibrator create(
            final NEDPosition position, final double turntableRotationRate, final double timeInterval,

final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,
            final double timeInterval, final List<StandardDeviationBodyKinematics> measurements,
            final boolean commonAxisUsed, final boolean estimateGDependentCrossBiases, final double[] bias,
            final Matrix initialMg, final Matrix initialGg, final double[] accelerometerBias,
            final Matrix accelerometerMa, final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa);
            case LMEDS -> new LMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa);
            case MSAC -> new MSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa);
            case PROSAC -> new PROSACRobustKnownBiasTurntableGyroscopeCalibrator(
                    qualityScores, position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa);
            default -> new PROMedSRobustKnownBiasTurntableGyroscopeCalibrator(
                    qualityScores, position, turntableRotationRate, timeInterval, measurements, commonAxisUsed,
                    estimateGDependentCrossBiases, bias, initialMg, initialGg, accelerometerBias, accelerometerMa);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param qualityScores                 quality scores corresponding to each provided
     *                                      measurement. The larger the score value the better
     *                                      the quality of the sample.
     * @param position                      position where body kinematics
     *                                      measures have been taken.
     * @param turntableRotationRate         constant rotation rate at which
     *                                      the turntable is spinning. Must
     *                                      be expressed in radians per
     *                                      second (rad/s).
     * @param timeInterval                  time interval between measurements
     *                                      being captured expressed in
     *                                      seconds (s).
     * @param measurements                  collection of body kinematics
     *                                      measurements with standard
     *                                      deviations taken at the same
     *                                      position with zero velocity
     *                                      and unknown different
     *                                      orientations.
     * @param commonAxisUsed                indicates whether z-axis is
     *                                      assumed to be common for
     *                                      accelerometer and gyroscope.
     * @param estimateGDependentCrossBiases true if G-dependent cross biases
     *                                      will be estimated, false
     *                                      otherwise.
     * @param bias                          known gyroscope bias. This must
     *                                      have length 3 and is expressed
     *                                      in radians per second (rad/s).
     * @param initialMg                     initial gyroscope scale factors
     *                                      and cross coupling errors matrix.
     *                                      Must be 3x3.
     * @param initialGg                     initial gyroscope G-dependent
     *                                      cross biases introduced on the
     *                                      gyroscope by the specific forces
     *                                      sensed by the accelerometer. Must
     *                                      be 3x3.
     * @param accelerometerBias             known accelerometer bias. This
     *                                      must have length 3 and is
     *                                      expressed in meters per squared
     *                                      second (m/s^2).
     * @param accelerometerMa               known accelerometer scale factors
     *                                      and cross coupling matrix. Must
     *                                      be 3x3.
     * @param listener                      listener to handle events raised
     *                                      by this calibrator.
     * @param method                        robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size, if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative or
     *                                  if provided quality scores length is
     *                                  smaller than 7 samples.
     */
    public static RobustKnownBiasTurntableGyroscopeCalibrator create(
            final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,

final ECEFPosition position, final double turntableRotationRate, final double timeInterval,
            final List<StandardDeviationBodyKinematics> measurements, final boolean commonAxisUsed,
            final boolean estimateGDependentCrossBiases, final Matrix initialBias, final Matrix initialMg,
            final Matrix initialGg, final Matrix accelerometerBias, final Matrix accelerometerMa,
            final RobustTurntableGyroscopeCalibratorListener listener, final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case LMEDS -> new LMedSRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case MSAC -> new MSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            case PROSAC -> new PROSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
            default -> new PROMedSRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa, listener);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param position              position where body kinematics measures
     *                              have been taken.
     * @param turntableRotationRate constant rotation rate at which the
     *                              turntable is spinning. Must be
     *                              expressed in radians per second (rad/s).
     * @param timeInterval          time interval between measurements being
     *                              captured expressed in seconds (s).
     * @param measurements          collection of body kinematics
     *                              measurements with standard deviations
     *                              taken at the same position with zero
     *                              velocity and unknown different
     *                              orientations.
     * @param initialBias           initial gyroscope bias to be used to
     *                              find a solution. This must be 3x1 and
     *                              is expressed in radians per second
     *                              (rad/s).
     * @param initialMg             initial gyroscope scale factors and
     *                              cross coupling errors matrix. Must
     *                              be 3x3.
     * @param initialGg             initial gyroscope G-dependent cross
     *                              biases introduced on the gyroscope by
     *                              the specific forces sensed by the
     *                              accelerometer. Must be 3x3.
     * @param method                robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size or if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative.
     */
    public static RobustTurntableGyroscopeCalibrator create(
            final NEDPosition position, final double turntableRotationRate, final double timeInterval,

final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,
            final double timeInterval, final List<StandardDeviationBodyKinematics> measurements,
            final boolean commonAxisUsed, final boolean estimateGDependentCrossBiases, final double[] initialBias,
            final Matrix initialMg, final Matrix initialGg, final double[] accelerometerBias,
            final Matrix accelerometerMa, final RobustEstimatorMethod method) {
        return switch (method) {
            case RANSAC -> new RANSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa);
            case LMEDS -> new LMedSRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa);
            case MSAC -> new MSACRobustTurntableGyroscopeCalibrator(position, turntableRotationRate, timeInterval,
                    measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg, initialGg,
                    accelerometerBias, accelerometerMa);
            case PROSAC -> new PROSACRobustTurntableGyroscopeCalibrator(qualityScores, position, turntableRotationRate,
                    timeInterval, measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg,
                    initialGg, accelerometerBias, accelerometerMa);
            default -> new PROMedSRobustTurntableGyroscopeCalibrator(qualityScores, position, turntableRotationRate,
                    timeInterval, measurements, commonAxisUsed, estimateGDependentCrossBiases, initialBias, initialMg,
                    initialGg, accelerometerBias, accelerometerMa);
        };
    }

    /**
     * Creates a robust gyroscope calibrator.
     *
     * @param qualityScores                 quality scores corresponding to each provided
     *                                      measurement. The larger the score value the better
     *                                      the quality of the sample.
     * @param position                      position where body kinematics
     *                                      measures have been taken.
     * @param turntableRotationRate         constant rotation rate at which
     *                                      the turntable is spinning. Must
     *                                      be expressed in radians per
     *                                      second (rad/s).
     * @param timeInterval                  time interval between measurements
     *                                      being captured expressed in
     *                                      seconds (s).
     * @param measurements                  collection of body kinematics
     *                                      measurements with standard
     *                                      deviations taken at the same
     *                                      position with zero velocity
     *                                      and unknown different
     *                                      orientations.
     * @param commonAxisUsed                indicates whether z-axis is
     *                                      assumed to be common for
     *                                      accelerometer and gyroscope.
     * @param estimateGDependentCrossBiases true if G-dependent cross
     *                                      biases will be estimated,
     *                                      false otherwise.
     * @param initialBias                   initial gyroscope bias to be
     *                                      used to find a solution. This
     *                                      must have length 3 and is
     *                                      expressed in radians per second
     *                                      (rad/s).
     * @param initialMg                     initial gyroscope scale factors
     *                                      and cross coupling errors
     *                                      matrix. Must be 3x3.
     * @param initialGg                     initial gyroscope G-dependent
     *                                      cross biases introduced on the
     *                                      gyroscope by the specific forces
     *                                      sensed by the accelerometer.
     *                                      Must be 3x3.
     * @param accelerometerBias             known accelerometer bias. This
     *                                      must have length 3 and is
     *                                      expressed in meters per squared
     *                                      second (m/s^2).
     * @param accelerometerMa               known accelerometer scale factors
     *                                      and cross coupling matrix. Must
     *                                      be 3x3.
     * @param listener                      listener to handle events raised
     *                                      by this calibrator.
     * @param method                        robust estimator method.
     * @return a robust gyroscope calibrator.
     * @throws IllegalArgumentException if any of the provided values does
     *                                  not have proper size, if either
     *                                  turntable rotation rate or
     *                                  time interval is zero or negative or
     *                                  if provided quality scores length is
     *                                  smaller than 10 samples.
     */
    public static RobustTurntableGyroscopeCalibrator create(
            final double[] qualityScores, final ECEFPosition position, final double turntableRotationRate,

PROMedSRobustKnownFrameMagnetometerCalibrator.this, progress);
                        }
                    }
                });

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            inliersData = null;

            setupWmmEstimator();

            innerEstimator.setUseInlierThresholds(true);
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            final var preliminaryResult = innerEstimator.estimate();
            inliersData = innerEstimator.getInliersData();

            attemptRefine(preliminaryResult);

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } catch (final RobustEstimatorException | IOException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROMEDS;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return true;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * This method is used internally and does not check whether instance is
     * locked or not.
     *
     * @param qualityScores quality scores to be set.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than 4 samples.
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores == null || qualityScores.length < MINIMUM_MEASUREMENTS) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}

PROMedSRobustKnownHardIronPositionAndInstantMagnetometerCalibrator.this,
                                    progress);
                        }
                    }
                });

        try {
            running = true;

            if (listener != null) {
                listener.onCalibrateStart(this);
            }

            inliersData = null;

            initialize();

            innerEstimator.setUseInlierThresholds(true);
            innerEstimator.setConfidence(confidence);
            innerEstimator.setMaxIterations(maxIterations);
            innerEstimator.setProgressDelta(progressDelta);
            final var preliminaryResult = innerEstimator.estimate();
            inliersData = innerEstimator.getInliersData();

            attemptRefine(preliminaryResult);

            if (listener != null) {
                listener.onCalibrateEnd(this);
            }

        } catch (final com.irurueta.numerical.LockedException e) {
            throw new LockedException(e);
        } catch (final com.irurueta.numerical.NotReadyException e) {
            throw new NotReadyException(e);
        } catch (final RobustEstimatorException | IOException e) {
            throw new CalibrationException(e);
        } finally {
            running = false;
        }
    }

    /**
     * Returns method being used for robust estimation.
     *
     * @return method being used for robust estimation.
     */
    @Override
    public RobustEstimatorMethod getMethod() {
        return RobustEstimatorMethod.PROMEDS;
    }

    /**
     * Indicates whether this calibrator requires quality scores for each
     * measurement or not.
     *
     * @return true if quality scores are required, false otherwise.
     */
    @Override
    public boolean isQualityScoresRequired() {
        return true;
    }

    /**
     * Sets quality scores corresponding to each provided sample.
     * This method is used internally and does not check whether instance is
     * locked or not.
     *
     * @param qualityScores quality scores to be set.
     * @throws IllegalArgumentException if provided quality scores length
     *                                  is smaller than 4 samples.
     */
    private void internalSetQualityScores(final double[] qualityScores) {
        if (qualityScores == null || qualityScores.length < MINIMUM_MEASUREMENTS_COMMON_Z_AXIS) {
            throw new IllegalArgumentException();
        }

        this.qualityScores = qualityScores;
    }
}